Chapter 12 Resource Masters Consumable Workbooks Many of the worksheets contained in the Chapter Resource Masters are available as consumable workbooks in both English and Spanish. Study Guide and Intervention Workbook Homework Practice Workbook ISBN10 0-07-890848-5 0-07-890849-3 ISBN13 978-0-07-890848-4 978-0-07-890849-1 Spanish Version Homework Practice Workbook 0-07-890853-1 978-0-07-890853-8 Answers for Workbooks The answers for Chapter 12 of these workbooks can be found in the back of this Chapter Resource Masters booklet. StudentWorks PlusTM This CD-ROM includes the entire Student Edition text along with the English workbooks listed above. TeacherWorks PlusTM All of the materials found in this booklet are included for viewing, printing, and editing in this CD-ROM. Spanish Assessment Masters (ISBN10: 0-07-890856-6, ISBN13: 978-0-07-890856-9) These masters contain a Spanish version of Chapter 12 Test Form 2A and Form 2C. Copyright © by The McGraw-Hill Companies, Inc. All rights reserved. Permission is granted to reproduce the material contained herein on the condition that such materials be reproduced only for classroom use; be provided to students, teachers, and families without charge; and be used solely in conjunction with the Glencoe Geometry program. Any other reproduction, for sale or other use, is expressly prohibited. Send all inquiries to: Glencoe/McGraw-Hill 8787 Orion Place Columbus, OH 43240-4027 ISBN: 978-0-07-890521-6 MHID: 0-07-890521-4 Printed in the United States of America. 6 7 8 9 10 11 12 REL 19 18 17 16 15 14 13 Contents Teacher’s Guide to Using the Chapter 12 Resource Masters .............................................iv Lesson 12-5 Chapter 12 Student-Built Glossary .................... 1 Chapter 12 Anticipation Guide (English) ........... 3 Chapter 12 Anticipation Guide (Spanish) .......... 4 Volumes of Pyramids and Cones Study Guide and Intervention .......................... 31 Skills Practice .................................................. 33 Practice............................................................ 34 Word Problem Practice ................................... 35 Enrichment ...................................................... 36 Lesson 12-1 Lesson 12-6 Chapter Resources Representations of Three-Dimensional Figures Study Guide and Intervention ............................ 5 Skills Practice .................................................... 7 Practice.............................................................. 8 Word Problem Practice ..................................... 9 Enrichment ...................................................... 10 Graphing Calculator Activity ............................ 11 Surface Areas and Volumes of Spheres Study Guide and Intervention .......................... 37 Skills Practice .................................................. 39 Practice............................................................ 40 Word Problem Practice ................................... 41 Enrichment ...................................................... 42 Lesson 12-7 Spherical Geometry Study Guide and Intervention .......................... 43 Skills Practice .................................................. 45 Practice............................................................ 46 Word Problem Practice ................................... 47 Enrichment ...................................................... 48 Lesson 12-2 Surface Area of Prisms and Cylinders Study Guide and Intervention .......................... 12 Skills Practice .................................................. 14 Practice............................................................ 15 Word Problem Practice ................................... 16 Enrichment ...................................................... 17 Lesson 12-8 Congruent and Similar Solids Study Guide and Intervention .......................... 49 Skills Practice .................................................. 51 Practice............................................................ 52 Word Problem Practice ................................... 53 Enrichment ...................................................... 54 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Lesson 12-3 Surface Area of Pyramids and Cones Study Guide and Intervention .......................... 18 Skills Practice .................................................. 20 Practice............................................................ 21 Word Problem Practice ................................... 22 Enrichment ...................................................... 23 Spreadsheet Activity ........................................ 24 Assessment Student Recording Sheet ................................ 55 Rubric for Extended-Response ....................... 56 Chapter 12 Quizzes 1 and 2 ........................... 57 Chapter 12 Quizzes 3 and 4 ........................... 58 Chapter 12 Mid-Chapter Test .......................... 59 Chapter 12 Vocabulary Test ........................... 60 Chapter 12 Test, Form 1 ................................. 61 Chapter 12 Test, Form 2A............................... 63 Chapter 12 Test, Form 2B............................... 65 Chapter 12 Test, Form 2C .............................. 67 Chapter 12 Test, Form 2D .............................. 69 Chapter 12 Test, Form 3 ................................. 71 Chapter 12 Extended-Response Test ............. 73 Standardized Test Practice ............................. 74 Lesson 12-4 Volumes of Prisms and Cylinders Study Guide and Intervention .......................... 25 Skills Practice .................................................. 27 Practice............................................................ 28 Word Problem Practice ................................... 29 Enrichment ...................................................... 30 Answers ........................................... A1–A36 iii Teacher’s Guide to Using the Chapter 12 Resource Masters The Chapter 12 Resource Masters includes the core materials needed for Chapter 12. These materials include worksheets, extensions, and assessment options. The answers for these pages appear at the back of this booklet. All of the materials found in this booklet are included for viewing and printing on the TeacherWorks PlusTM CD-ROM. Chapter Resources Practice This master closely follows the types of problems found in the Exercises section of the Student Edition and includes word problems. Use as an additional practice option or as homework for second-day teaching of the lesson. Student-Built Glossary (pages 1–2) These masters are a student study tool that presents up to twenty of the key vocabulary terms from the chapter. Students are to record definitions and/or examples for each term. You may suggest that students highlight or star the terms with which they are not familiar. Give this to students before beginning Lesson 12–1. Encourage them to add these pages to their mathematics study notebooks. Remind them to complete the appropriate words as they study each lesson. Word Problem Practice This master includes additional practice in solving word problems that apply the concepts of the lesson. Use as an additional practice or as homework for second-day teaching of the lesson. Anticipation Guide (pages 3–4) This master, presented in both English and Spanish, is a survey used before beginning the chapter to pinpoint what students may or may not know about the concepts in the chapter. Students will revisit this survey after they complete the chapter to see if their perceptions have changed. Graphing Calculator, TI-Nspire, or Spreadsheet Activities These activities present ways in which technology can be used with the concepts in some lessons of this chapter. Use as an alternative approach to some concepts or as an integral part of your lesson presentation. Lesson Resources Study Guide and Intervention These masters provide vocabulary, key concepts, additional worked-out examples and Check Your Progress exercises to use as a reteaching activity. It can also be used in conjunction with the Student Edition as an instructional tool for students who have been absent. Skills Practice This master focuses more on the computational nature of the lesson. Use as an additional practice option or as homework for second-day teaching of the lesson. iv Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Enrichment These activities may extend the concepts of the lesson, offer a historical or multicultural look at the concepts, or widen students’ perspectives on the mathematics they are learning. They are written for use with all levels of students. Assessment Options Leveled Chapter Tests • Form 1 contains multiple-choice questions and is intended for use with approaching grade level students. • Forms 2A and 2B contain multiplechoice questions aimed at on grade level students. These tests are similar in format to offer comparable testing situations. • Forms 2C and 2D contain free-response questions aimed at on grade level students. These tests are similar in format to offer comparable testing situations. • Form 3 is a free-response test for use with beyond grade level students. The assessment masters in the Chapter 12 Resource Masters offer a wide range of assessment tools for formative (monitoring) assessment and summative (final) assessment. Student Recording Sheet This master corresponds with the standardized test practice at the end of the chapter. Extended-Response Rubric This master provides information for teachers and students on how to assess performance on open-ended questions. Quizzes Four free-response quizzes offer assessment at appropriate intervals in the chapter. All of the above mentioned tests include a free-response Bonus question. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Mid-Chapter Test This 1-page test provides an option to assess the first half of the chapter. It parallels the timing of the Mid-Chapter Quiz in the Student Edition and includes both multiple-choice and free-response questions. Extended-Response Test Performance assessment tasks are suitable for all students. Sample answers and a scoring rubric are included for evaluation. Standardized Test Practice These three pages are cumulative in nature. It includes three parts: multiple-choice questions with bubble-in answer format, griddable questions with answer grids, and short-answer free-response questions. Vocabulary Test This test is suitable for all students. It includes a list of vocabulary words and 12 questions to assess students’ knowledge of those words. This can also be used in conjunction with one of the leveled chapter tests. Answers • The answers for the Anticipation Guide and Lesson Resources are provided as reduced pages. • Full-size answer keys are provided for the assessment masters. v NAME DATE 12 PERIOD This is an alphabetical list of the key vocabulary terms you will learn in Chapter 12. As you study the chapter, complete each term’s definition or description. Remember to add the page number where you found the term. Add these pages to your Geometry Study Notebook to review vocabulary at the end of the chapter. Vocabulary Term Found on Page Definition/Description/Example altitude axis congruent solids Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. cross section Euclidean geometry great circle isometric view lateral area lateral edge lateral face (continued on the next page) Chapter 12 1 Glencoe Geometry Chapter Resources Student-Built Glossary NAME DATE 12 PERIOD Student-Built Glossary (continued) Vocabulary Term Found on Page Definition/Description/Example oblique cone oblique cylinder oblique prism regular pyramid right cone Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. right cylinder right prism (PRIZ·uhm) similar solids slant height spherical geometry Chapter 12 2 Glencoe Geometry NAME 12 DATE PERIOD Anticipating Guide Step 1 Before you begin Chapter 12 • Read each statement. • Decide whether you Agree (A) or Disagree (D) with the statement. • Write A or D in the first column OR if you are not sure whether you agree or disagree, write NS (Not Sure). STEP 1 A, D, or NS STEP 2 A or D Statement 1. The shape of a horizontal cross section of a square pyramid is a triangle. 2. The lateral area of a prism is equal to the sum of the areas of each face. 3. The axis of an oblique cylinder is different than the height of the cylinder. 4. The slant height and height of a regular pyramid are the same. 5. The lateral area of a cone equals the product of π, the radius, and the height of the cone. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 6. The volume of a right cylinder with radius r and height h is πr2h. 7. The volume of a pyramid or a cone is found by multiplying the area of the base by the height. 8. To find the surface area of a sphere with radius r, multiply πr2 by 4. 9. All postulates and properties of Euclidean geometry are true in spherical geometry. 10. All spheres and all cubes are similar solids. • After you complete Chapter 12 Step 2 Reread each statement and complete the last column by entering an A or a D. • Did any of your opinions about the statements change from the first column? • For those statements that you mark with a D, use a piece of paper to write an example of why you disagree. Chapter 12 3 Glencoe Geometry Chapter Resources Extending Surface Area and Volume NOMBRE 12 FECHA PERÍODO Ejercicios Preparations Extiende el Área de Superficie y volumen Paso 1 Antes de comenzar el Capítulo 12 • Lee cada enunciado. • Decide si estás de acuerdo (A) o en desacuerdo (D) con el enunciado. • Escribe A o D en la primera columna O si no estás seguro(a) de la respuesta, escribe NS (No estoy seguro(a). PASO 1 A, D o NS PASO 2 AoD Enunciado 1. La forma de un corte transversal horizontal de una pirámide cuadrada es un triángulo. 2. El área lateral de un prisma es igual a la suma de las áreas de cada cara. 3. El eje de un cilindro oblicuo es diferente a la altura del cilindro. 4. La altura oblicua y la altura de una pirámide regular son las mismas. 5. El área lateral de un cono es igual al producto de π, el radio, por la altura del cono. 6. El volumen de un cilindro recto con radio r y altura h es πr2h. 8. Para calcular el área de superficie de una esfera con radio r, multiplica πr2 por 4. 9. Todos los postulados y propiedades de la geometría euclidiana son verdaderos en geometría esférica. 10. Todas las esferas y todos los cubos son sólidos semejantes. Paso 2 Después de completar el Capítulo 12 • Vuelve a leer cada enunciado y completa la última columna con una A o una D. • ¿Cambió cualquiera de tus opiniones sobre los enunciados de la primera columna? • En una hoja de papel aparte, escribe un ejemplo de por qué estás en desacuerdo con los enunciados que marcaste con una D. Capítulo 12 4 Geometría de Glencoe Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 7. El volumen de una pirámide o un cono se calcula multiplicando el área de la base por la altura. NAME DATE 12-1 PERIOD Study Guide and Intervention Representations of Three-Dimensional Figures Draw Isometric Views Isometric dot paper can be used to draw isometric views, or corner views, of a three-dimensional object on two-dimensional paper. A B E Example 2 Use isometric dot paper and the orthographic drawing to sketch a solid. • The top view indicates two columns. top view left view • The right and left views indicate that the height of figure is three blocks. • The front view indicates that the columns have heights 2 and 3 blocks. F front view Connect the dots on the isometric dot paper to represent the edges of the solid. Shade the tops of each column. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. C D right view object Exercises Sketch each solid using isometric dot paper. 1. cube with 4 units on each side 2. rectangular prism 1 unit high, 5 units long, and 4 units wide Use isometric dot paper and each orthographic drawing to sketch a solid. 3. 4. top view Chapter 12 left view front view top view right view 5 left view front view right view Glencoe Geometry Lesson 12 -1 Example 1 Use isometric dot paper to sketch a triangular prism 3 units high, with two sides of the base that are 3 units long and 4 units long. −− −− Step 1 Draw AB at 3 units and draw AC at 4 units. −−− −−− −− Step 2 Draw AD, BE, and CF, each at 3 units. −−− Step 3 Draw BC and DEF. NAME 12-1 DATE PERIOD Study Guide and Intervention (continued) Representations of Three-Dimensional Figures Cross Sections The intersection of a solid and a plane is called a cross section of the solid. The shape of a cross section depends upon the angle of the plane. Example There are several interesting shapes that are cross sections of a cone. Determine the shape resulting from each cross section of the cone. If the plane is parallel to the base of the cone, then the resulting cross section will be a circle. b. If the plane cuts through the cone perpendicular to the base and through the center of the cone, then the resulting cross section will be a triangle. c. If the plane cuts across the entire cone, then the resulting cross section will be an ellipse. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. a. Exercises Describe each cross section. 1. Chapter 12 2. 3. 6 Glencoe Geometry NAME 12-1 DATE PERIOD Skills Practice Representations of Three-Dimensional Figures Use isometric dot paper to sketch each prism. 2. rectangular prism 2 units high, 5 units long, and 2 units wide Use isometric dot paper and each orthographic drawing to sketch a solid. 3. 4. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. top view left view front view right view top view left view front view right view Describe each cross section. 5. 6. 7. 8. Chapter 12 7 Glencoe Geometry Lesson 12-1 1. cube 2 units on each edge NAME DATE 12-1 PERIOD Practice Representations of Three-Dimensional Figures Use isometric dot paper to sketch each prism. 1. rectangular prism 3 units high, 3 units long, and 2 units wide 2. triangular prism 3 units high, whose bases are right triangles with legs 2 units and 4 units long Use isometric dot paper and each orthographic drawing to sketch a solid. 3. 4. top view left view front view right view top view left view front view right view 5. 6. 7. SPHERES Consider the sphere in Exercise 5. Based on the cross section resulting from a horizontal and a vertical slice of the sphere, make a conjecture about all spherical cross sections. 8. MINERALS Pyrite, also known as fool’s gold, can form crystals that are perfect cubes. Suppose a gemologist wants to cut a cube of pyrite to get a square and a rectanglar face. What cuts should be made to get each of the shapes? Illustrate your answers. Chapter 12 8 Glencoe Geometry Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Sketch the cross section from a vertical slice of each figure. NAME 12-1 DATE PERIOD Word Problem Practice Representations of Three-Dimensional Figures 4. ENGINEERING Stephanie needs an object whose top view is a circle and whose left and front views are squares. Describe an object that will satisfy these conditions. 2. BLOCKS Margot’s three-year-old son made the magnetic block sculpture shown below in corner view. 5. DESK SUPPORTS The figure shows the support for a desk. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Draw the right view of the sculpture. a. Draw the top view. b. Draw the front view. 3. CUBES Nathan marks the midpoints of three edges of a cube as shown. He then slices the cube along a plane that contains these three points. Describe the resulting cross section. Chapter 12 c. Draw the right view. 9 Glencoe Geometry Lesson 12-1 1. LABELS Jamal removes the label from a cylindrical soup can to earn points for his school. Sketch the shape of the label. NAME 12-1 DATE PERIOD Enrichment Drawing Solids on Isometric Dot Paper Isometric dot paper is helpful for drawing solids. Remember to use dashed lines for hidden edges. For each solid shown, draw another solid whose dimensions are twice as large. 2. 3. 4. 5. 6. Chapter 12 10 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 1. Glencoe Geometry NAME 12-1 DATE PERIOD Graphing Calculator Activity Perspective Drawings The science of perspective drawing studies how to draw a threedimensional object on a two-dimensional page. This science became highly refined during the Renaissance with the work of artists such as Albrecht Dürer and Leonardo da Vinci. Lesson 12-1 Today, computers are often used to make perspective drawings, particularly elaborate graphics used in television and movies. The three-dimensional coordinates of objects are figured. Then algebra is used to transform these into two-dimensional coordinates. The graph of these new coordinates is called a projection. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. The formulas below will draw one type of projection in which the y-axis is drawn horizontally, the z-axis vertically, and the x-axis at an angle of a˚ with the y-axis. If the three-dimensional coordinates of a point are (x, y, z), then the projection coordinates (X, Y) are given by X = x(-cos a) + y and Y = x(-sin a) + z. Although this type of projection gives a fairly good perspective drawing, it does distort some lengths. 1. The drawing with the coordinates given below is a cube. A(5, 0, 5), B(5, 5, 5), C(5, 5, 0), D(5, 0, 0), E(0, 0, 5), F(0, 5, 5), G(0, 5, 0), H(0, 0, 0) Use the formulas above to find the projection coordinates of each A point, using a = 45. Round projection coordinates to the nearest integer. Graph the cube on a graphing calculator. Make a sketch of the display. A'(__, __) B'(__, __) C(__, __) D(__, __) E'(__, __) F'(__, __) D G(__, __) H(__, __) E F B H G C 2. The points A(10, 2, 0), B(10, 10, 0), C(2, 10, 0), and D(3, 3, 4) are vertices of a pyramid. Find the projection coordinates, using a = 25. Round coordinates to the nearest integer. −−− −−− −−− −−− Then graph the pyramid on a graphing calculator by drawing AB, BC, CD, DA, −−− and DB. Make a sketch of the display. A(__, __) B(__, __) C(__, __) D(__, __) Chapter 12 11 Glencoe Geometry NAME DATE 12-2 PERIOD Study Guide and Intervention Surface Areas of Prisms and Cylinders Lateral and Surface Areas of Prisms In a solid figure, faces that are not bases are lateral faces. The lateral area is the sum of the area of the lateral faces. The surface area is the sum of the lateral area and the area of the bases. altitude lateral edge Lateral Area of a Prism If a prism has a lateral area of L square units, a height of h units, and each base has a perimeter of P units, then L = Ph. Surface Area of a Prism If a prism has a surface area of S square units, a lateral area of L square units, and each base has an area of B square units, then S = L + 2B or S = Ph + 2B lateral face pentagonal prism Example Find the lateral and surface area of the regular pentagonal prism above if each base has a perimeter of 75 centimeters and the height is 10 centimeters. L = Ph = 75(10) = 750 Lateral area of a prism P = 75, h = 10 Multiply. S = L + 2B 1 = 750 + 2 − aP (2 ) ( 36° ) 7.5 = 750 + − (75) tan 36° a 15 cm ≈ 1524.2 7.5 tan 36° = − a 7.5 a=− tan 36° Exercises Find the lateral area and surface area of each prism. Round to the nearest tenth if necessary. 2. 1. 3m 10 in. 10 m 4m 15 in. 3. 4. 10 cm 9 cm 6 in. 18 in. 5. Chapter 12 10 cm 8 cm 12 cm 20 cm 4 in. 4 in. 8 in. 6. 12 in. 4m 12 16 m Glencoe Geometry Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. The lateral area is 750 square centimeters and the surface area is about 1524.2 square centimeters. NAME DATE 12-2 PERIOD Study Guide and Intervention (continued) Surface Areas of Prisms and Cylinders Lateral and Surface Areas of Cylinders A cylinder is a solid with bases that are congruent circles lying in parallel planes. The axis of a cylinder is the segment with endpoints at the centers of these circles. For a right cylinder, the axis is also the altitude of the cylinder. base height axis base radius of base Lateral Area of a Cylinder If a cylinder has a lateral area of L square units, a height of h units, and a base has a radius of r units, then L = 2πrh. Surface Area of a Cylinder If a cylinder has a surface area of S square units, a height of h units, and a base has a radius of r units, then S = L + 2B or 2πrh + 2πr2. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Find the lateral and surface area of the cylinder. Round to the nearest tenth. If d = 12 cm, then r = 6 cm. L = 2πrh Lateral area of a cylinder = 2π(6)(14) r = 6, h = 14 12 cm ≈ 527.8 Use a calculator. S = 2πrh + 2πr2 Surface area of a cylinder 2 ≈ 527.8 + 2π(6) 2πrh ≈ 527.8, r = 6 ≈ 754.0 Use a calculator. The lateral area is about 527.8 square centimeters and the surface area is about 754.0 square centimeters. 14 cm Exercises Find the lateral area and surface area of each cylinder. Round to the nearest tenth. 1. 2. 4 cm 10 in. 6 in. 12 cm 3. 4. 3 cm 8 cm 3 cm 6 cm 5. 20 cm 6. 2m 1m 12 m 4m Chapter 12 13 Glencoe Geometry Lesson 12-2 Example NAME DATE 12-2 PERIOD Skills Practice Surface Areas of Prisms and Cylinders Find the lateral area and surface area of each prism. Round to the nearest tenth if necessary. 1. 2. 6m 12 yd 12 m 10 yd 8m 12 yd 3. 4. 6 in. 9 cm 7.8 cm 8 in. 9 cm 12 cm 5 in. 9 cm 10 in. 5. 6. 2m 10 in. 2m 12 in. 7. 3 yd 8. 8 in. 12 in. 2 yd Chapter 12 14 Glencoe Geometry Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Find the lateral area and surface area of each cylinder. Round to the nearest tenth. NAME DATE 12-2 PERIOD Practice Surface Areas of Prisms and Cylinders Find the lateral and surface area of each prism. Round to the nearest tenth if necessary. 2. 1. 15 cm 32 cm 5 ft 10 ft 8 ft 15 cm 4. 4 yd 4 yd 2m Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 9.5 yd 11 m Lesson 12-2 3. 5 yd Find the lateral area and surface area of each cylinder. Round to the nearest tenth. 5. 5 ft 6. 4m 7 ft 8.5 m 7. 19 in. 8. 17 in. 12 m Chapter 12 15 30 m Glencoe Geometry NAME 12-2 DATE PERIOD Word Problem Practice Surface Areas of Prisms and Cylinders 1. LOGOS The Z company specializes in caring for zebras. They want to make a 3-dimensional “Z” to put in front of their company headquarters. The “Z” is 15 inches thick and the perimeter of the base is 390 inches. 4. EXHAUST PIPES An exhaust pipe is shaped like a cylinder with a height of 50 inches and a radius of 2 inches. What is the lateral surface area of the exhaust pipe? Round your answer to the nearest hundredth. 15" 5. TOWERS A circular tower is made by placing one cylinder on top of another. Both cylinders have a height of 18 inches. The top cylinder has a radius of 18 inches and the bottom cylinder has a radius of 36 inches. What is the lateral surface area of this “Z”? 2. STAIRWELLS Management decides to enclose stairs connecting the first and second floors of a parking garage in a stairwell shaped like an oblique rectangular prism. 18 in. 18 in. 9 ft 16 ft 15 ft What is the lateral surface area of the stairwell? b. Another tower is constructed by placing the original tower on top of another cylinder with a height of 18 inches and a radius of 54 inches. What is the total surface area of the new tower? Round your answer to the nearest hundredth. 3. CAKES A cake is a rectangular prism with height 4 inches and base 12 inches by 15 inches. Wallace wants to apply frosting to the sides and the top of the cake. What is the surface area of the part of the cake that will have frosting? Chapter 12 16 Glencoe Geometry Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. a. What is the total surface area of the tower? Round your answer to the nearest hundredth. 20 ft NAME DATE 12-2 PERIOD Enrichment Minimizing Cost in Manufacturing Suppose that a manufacturer wants to make a can that has a volume of 40 cubic inches. The cost to make the can is 3 cents per square inch for the top and bottom and 1 cent per square inch for the side. r h 1. Write the value of h in terms of r, given v = πr 2 h. 2. Write a formula for the cost in terms of r. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 4. Repeat the procedure using 2 cents per square inch for the top and bottom and 4 cents per square inch for the top and bottom. 5. What would you expect to happen as the cost of the top and bottom increases? 6. Compute the table for the cost value given. What happens to the height of the can as the cost of the top and bottom increases? Cost Top Cost Minimum & Bottom Cylinder h 2 cents 1 cent 3 cents 1 cent 4 cents 1 cent 5 cents 1 cent 6 cents 1 cent Chapter 12 17 Glencoe Geometry Lesson 12-2 3. Use a graphing calculator to graph the formula, letting Y1 represent the cost and X represent r. Use the graph to estimate the point at which the cost is minimized. NAME 12-3 DATE PERIOD Study Guide and Intervention Surface Areas of Pyramids and Cones Lateral and Surface Areas of Pyramids A pyramid is a solid with a polygon base. The lateral faces intersect in a common slant height point known as the vertex. The altitude is the segment from the vertex that is perpendicular to the base. For a regular pyramid, the base is a regular polygon and the altitude has an endpoint at the center of the base. All the lateral edges are congruent and all the lateral faces are congruent isosceles triangles. The height of each lateral face is called the slant height. Lateral Area of a Regular Pyramid Surface Area of a Regular Pyramid lateral edge height base 1 The lateral area L of a regular pyramid is L = − Pℓ, where ℓ 2 is the slant height and P is the perimeter of the base. 1 The surface area S of a regular pyramid is S = − Pℓ + B, 2 where ℓ is the slant height, P is the perimeter of the base, and B is the area of the base. Example For the regular square pyramid above, find the lateral area and surface area if the length of a side of the base is 12 centimeters and the height is 8 centimeters. Round to the nearest tenth if necessary. Find the slant height. ℓ2 = 62 + 82 Pythagorean Theorem 2 ℓ = 100 Simplify. ℓ = 10 Take the positive square root of each side. Lateral area of a regular pyramid 2 1 = − (48)(10) 2 = 240 1 S=− Pℓ + B Surface area of a regular pyramid 2 P = 4 12 or 48, ℓ = 10 = 240 + 144 Simplify. = 384 1 − Pℓ = 240, B = 12 · 12 or 144 2 The lateral area is 240 square centimeters, and the surface area is 384 square centimeters. Exercises Find the lateral area and surface area of each regular pyramid. Round to the nearest tenth if necessary. 2. 1. 8 ft 20 cm 45° 15 cm 3. 10 cm 4. 8.7 in. 6 in. 60° Chapter 12 18 15 in. Glencoe Geometry Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 1 L=− Pℓ NAME DATE 12-3 PERIOD Study Guide and Intervention (continued) Surface Areas of Pyramids and Cones Lateral and Surface Areas of Cones A cone has V V altitude a circular base and a vertex. The axis of the cone is the segment with endpoints at the vertex and the center of the base. If the axis is also the altitude, then the cone is a right cone. If the axis is not the altitude, then the cone is an oblique cone. axis slant height base oblique cone Lateral Area of a Cone The lateral area L of a right circular cone is L = πr, where r is the radius and is the slant height. Surface Area of a Cone The surface area S of a right cone is S = πr + πr2, where r is the radius and is the slant height. base right cone Example For the right cone above, find the lateral area and surface area if the radius is 6 centimeters and the height is 8 centimeters. Round to the nearest tenth if necessary. L = πrℓ = π(6)(10) ≈ 188.5 Lateral area of a right cone r = 6, ℓ = 10 Simplify. S = πrℓ + πr2 ≈ 188.5 + π(62) ≈ 301.6 Surface area of a right cone πrℓ ≈ 188.5, r = 6 Simplify. The lateral area is about 188.5 square centimeters and the surface area is about 301.6 square centimeters. Exercises Find the lateral area and surface area of each cone. Round to the nearest tenth if necessary. 1. 12 cm 2. 5 ft 9 cm 3. 12 cm 30° 4. 45° 13 cm 4 in. Chapter 12 19 Glencoe Geometry Lesson 12-3 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Find the slant height. ℓ2 = 62 + 82 Pythagorean Theorem 2 ℓ = 100 Simplify. ℓ = 10 Take the positive square root of each side. NAME 12-3 DATE PERIOD Skills Practice Surface Areas of Pyramids and Cones Find the lateral area and surface area of each regular pyramid. Round to the nearest tenth if necessary. 1. 2. 20 in. 7 cm 4 cm 3. 9m 8 in. 4. 12 ft 10 m 14 ft Find the lateral area and surface area of each cone. Round to the nearest tenth. 5. 6. 10 ft 14 m 25 ft 7. 8. 21 in. 9 mm 17 mm 8 in. Chapter 12 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 5m 20 Glencoe Geometry NAME DATE 12-3 PERIOD Practice Surface Areas of Pyramids and Cones Find the lateral area and surface area of each regular pyramid. Round to the nearest tenth if necessary. 1. 2. 12 m 10 yd 7m 9 yd 3. 4. 8 cm 13 ft 5 ft 2.5 cm Find the lateral area and surface area of each cone. Round to the nearest tenth if necessary. 6. 5m 7 cm 4m 21 cm 7. Find the surface area of a cone if the height is 14 centimeters and the slant height is 16.4 centimeters. 8. Find the surface area of a cone if the height is 12 inches and the diameter is 27 inches. 9. GAZEBOS The roof of a gazebo is a regular octagonal pyramid. If the base of the pyramid has sides of 0.5 meter and the slant height of the roof is 1.9 meters, find the area of the roof. 10. HATS Cuong bought a conical hat on a recent trip to central Vietnam. The basic frame of the hat is 16 hoops of bamboo that gradually diminish in size. The hat is covered in palm leaves. If the hat has a diameter of 50 centimeters and a slant height of 32 centimeters, what is the lateral area of the conical hat? Chapter 12 21 Glencoe Geometry Lesson 12-3 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 5. NAME 12-3 DATE PERIOD Word Problem Practice Surface Areas of Pyramids and Cones 1. PAPER MODELS Patrick is making a paper model of a castle. Part of the model involves 20 cm 20 cm 15 cm cutting out the net shown and folding it into a pyramid. The pyramid has a square base. What is the lateral surface area of the resulting pyramid? 4. SPRAY PAINT A can of spray paint shoots out paint in a cone shaped mist. The lateral surface area of the cone is 65π square inches when the can is held 12 inches from a canvas. What is the area of the part of the canvas that gets sprayed with paint? Round your answer to the nearest hundredth. 5. MEGAPHONES A megaphone is formed by taking a cone with a radius of 20 centimeters and an altitude of 60 centimeters and cutting off the tip. The cut is made along a plane that is perpendicular to the axis of the cone and intersects the axis 12 centimeters from the vertex. Round your answers to the nearest hundredth. 3. PAPERWEIGHTS Daphne uses a paperweight shaped like a pyramid with a regular hexagon for a base. The side length of the regular hexagon is 1 inch. The altitude of the pyramid is 2 inches. a. What is the lateral surface area of the original cone? b. What is the lateral surface area of the tip that is removed? c. What is the lateral surface area of the megaphone? What is the lateral surface area of this pyramid? Round your answers to the nearest hundredth. Chapter 12 22 Glencoe Geometry Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 2. TETRAHEDRON Sung Li builds a paper model of a regular tetrahedron, a pyramid with an equilateral triangle for the base and three equilateral triangles for the lateral faces. One of the faces of the tetrahedron has an area of 17 square inches. What is the total surface area of the tetrahedron? NAME DATE 12-3 PERIOD Enrichment Cone Patterns The pattern at the right is made from a circle. It can be folded to make a cone. 1. Measure the radius of the circle to the nearest centimeter. 2. The pattern is what fraction of the complete circle? 3. What is the circumference of the complete circle? 4. How long is the circular arc that is the outside of the pattern? 5. Cut out the pattern and tape it together to form a cone. 6. Measure the diameter of the circular base of the cone. 8. What is the slant height of the cone? Lesson 12-3 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 7. What is the circumference of the base of the cone? 9. Use the Pythagorean Theorem to calculate the height of the cone. Use a decimal approximation. Check your calculation by measuring the height with a metric ruler. 10. Find the lateral area. 11. Find the total surface area. Make a paper pattern for each cone with the given measurements. Then cut the pattern out and make the cone. Find the measurements. 12. 13. 6 cm 20 cm 120° diameter of base = diameter of base = lateral area = lateral area = height of cone = (to nearest tenth of a centimeter) height of cone = (to nearest tenth of a centimeter) Chapter 12 23 Glencoe Geometry NAME DATE 12-3 PERIOD Spreadsheet Activity Surface Areas of Cones You can use a spreadsheet to determine the surface area of a cone. Example 1 Lucy wants to wrap a Mother’s Day gift. The gift she has bought for her mother is in a conical box that has a slant height of 6 inches and has a radius of 3 inches. She must determine the surface area of the box to determine how much wrapping paper to buy. Use a spreadsheet to determine the surface area of the box. Round to the nearest tenth. Step 1 Use cell A1 for the radius of the cone and cell B1 for the height. Step 2 In cell C1, enter an equals sign followed by PI()*A1*B1 + PI()*A1^2. Then press ENTER. This will return the surface area of the cone. The surface area of the conical box is 84.8 in2 to the nearest tenth. Example 2 Use a spreadsheet to determine the surface area of a cone that has a radius of 2.5 centimeters and a slant height of 5.2 centimeters. Round to the nearest tenth. A B C 1 2 Sheet 1 Use cell A2 for the radius of the cone and cell B2 for the slant height. Step 2 Click on the bottom right corner of cell C1 and drag it to C2. This returns the surface area of the cone. The surface area of the cone is 60.5 cm2 to the nearest tenth. Exercises Use a spreadsheet to find the surface area of each cone with the given dimensions. Round to the nearest tenth. 1. r = 12 m, = 2.3 m 2. r = 6 m, = 2 m 3. r = 3 in., = 7 in. 4. r = 5 in., = 11 in. 5. r = 1 ft, = 3 ft 6. r = 3 ft, = 1.5 ft 7. r = 10 mm, = 20 mm 8. r = 1.5 mm, = 4.5 mm 9. r = 6.2 cm, = 1.2 cm 10. r = 10 cm, = 15 cm 11. r = 10 m, = 2 m 12. r = 11 m, = 13 m Chapter 12 24 Glencoe Geometry Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Step 1 NAME DATE 12-4 PERIOD Study Guide and Intervention Volumes of Prisms and Cylinders Volumes of Prisms The measure of the amount of space that a three-dimensional figure encloses is the volume of the figure. Volume is measured in units such as cubic feet, cubic yards, or cubic meters. One cubic unit is the volume of a cube that measures one unit on each edge. Volume of a Prism If a prism has a volume of V cubic units, a height of h units, and each base has an area of B square units, then V = Bh. Example 1 of the prism. Example 2 Find the volume of the prism if the area of each base is 6.3 square feet. Find the volume 4 cm base 3 cm 7 cm 3.5 ft V = Bh Volume of a prism = (7)(3)(4) B = (7)(3), h = 4 = 84 Multiply. The volume of the prism is 84 cubic centimeters. V = Bh Volume of a prism = (6.3)(3.5) B = 6.3, h = 3.5 = 22.05 Multiply. The volume is 22.05 cubic feet. Exercises Find the volume of each prism. 1. 4 cm 3 cm 4. 12 ft 15 ft 5. 1.5 cm 8 ft 8 ft 3. 2. 8 ft 12 ft 10 ft 30° 15 ft 6. 2 cm 3 yd 1.5 cm 6 cm 4 cm Chapter 12 Lesson 12-4 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. cubic foot cubic yard 27 cubic feet = 1 cubic yard 7 yd 25 4 yd Glencoe Geometry NAME DATE 12-4 PERIOD Study Guide and Intervention (continued) Volumes of Prisms and Cylinders Volumes of Cylinders The volume of a cylinder is the product of the height and the area of the base. When a solid is not a right solid, use Cavalieri’s Priniciple to find the volume. The principle states that if two solids have the same height and the same cross sectional area at every level, then they have the same volume. Volume of a Cylinder r h If a cylinder has a volume of V cubic units, a height of h units, and the bases have a radius of r units, then V = πr 2h. Example 1 Find the volume of the cylinder. Example 2 Find the volume of the oblique cylinder. 3 cm 4 cm 13 in. h 8 in. 5 in. V = πr2h Volume of a cylinder 2 = π(3) (4) r = 3, h = 4 ≈ 113.1 Simplify. The volume is about 113.1 cubic centimeters. Use the Pythagorean Theorem to find the height of the cylinder. h2 + 52 = 132 Pythagorean Theorem 2 h = 144 Simplify. h = 12 Take the positive square root of each side. Exercises Find the volume of each cylinder. Round to the nearest tenth. 1. 2. 2 cm 2 ft 18 cm 1 ft 3. 4. 1.5 ft 12 ft 5. 20 ft 20 ft 6. 10 cm 1 yd 13 cm Chapter 12 26 4 yd Glencoe Geometry Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. V = πr2h Volume of a cylinder 2 = π(4) (12) r = 4, h = 12 ≈ 603.2 Simplify. The Volume is about 603.2 cubic inches. NAME DATE 12-4 PERIOD Skills Practice Volumes of Prisms and Cylinders Find the volume of each prism or cylinder. Round to the nearest tenth if necessary. 1. 2. 8 cm 2 ft 8 ft 16 cm 18 cm 6 ft 3. 4. 34 in. 13 m 5m 16 in. 22 in. 3m 5. 6. 10 yd 15 mm Find the volume of each oblique prism or cylinder. Round to the nearest tenth if necessary. 7. 4 cm 8. 18 cm 5 in. 17 cm Chapter 12 Lesson 12-4 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 23 mm 6 yd 3 in. 27 Glencoe Geometry NAME DATE 12-4 PERIOD Practice Volumes of Prisms and Cylinders Find the volume of each prism or cylinder. Round to the nearest tenth if necessary. 1. 2. 26 m 5 in. 10 m 17 m 5 in. 9 in. 5 in. 3. 4. 16 mm 25 ft 7 ft 17.5 mm 5. 8 cm 6. 10 yd 30 cm 20 yd 13 yd 2 a. What is the volume of the aquarium in cubic feet? b. If there are 7.48 gallons in a cubic foot, how many gallons of water does the aquarium hold? c. If a cubic foot of water weighs about 62.4 pounds, what is the weight of the water in the aquarium to the nearest five pounds? Chapter 12 28 Glencoe Geometry Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 7. AQUARIUM Mr. Gutierrez purchased a cylindrical aquarium for his office. 1 The aquarium has a height of 25 − inches and a radius of 21 inches. NAME 12-4 DATE PERIOD Word Problem Practice Volumes of Prisms and Cylinders 1. TRASH CANS The Meyer family uses a kitchen trash can shaped like a cylinder. It has a height of 18 inches and a base diameter of 12 inches. What is the volume 18 in. of the trash can? Round your answer to the nearest tenth of a cubic inch. 4. PENCIL GRIPS A pencil grip is shaped like a triangular prism with a cylinder removed from the middle. The base of the prism is a right isosceles triangle with leg lengths of 2 centimeters. The diameter of the base of the removed cylinder is 1 centimeter. The heights of the prism and the cylinder are the same, and equal to 4 centimeters. 12 in. 2. BENCH Inside a lobby, there is a piece of furniture for sitting. The furniture is shaped like a simple block with a square base 6 feet on each side and a height of 3 1− feet. 5 What is the exact volume of the pencil grip? 3 6 ft 6 ft 5. TUNNELS Construction workers are digging a tunnel through a mountain. The space inside the tunnel is going to be shaped like a rectangular prism. The mouth of the tunnel will be a rectangle 20 feet high and 50 feet wide and the length of the tunnel will be 900 feet. What is the volume of the seat? 3. FRAMES Margaret makes a square frame out of four pieces of wood. Each piece of wood is a rectangular prism with a length of 40 centimeters, a height of 4 centimeters, and a depth of 6 centimeters. What is the total volume of the wood used in the frame? Chapter 12 a. What will the volume of the tunnel be? b. If instead of a rectangular shape, the tunnel had a semicircular shape with a 50-foot diameter, what would be its volume? Round your answer to the nearest cubic foot. 29 Glencoe Geometry Lesson 12-4 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 1 5 ft NAME 12-4 DATE PERIOD Enrichment Visible Surface Area Use paper, scissors, and tape to make five cubes that have one-inch edges. Arrange the cubes to form each shape shown. Then find the volume and the visible surface area. In other words, do not include the area of surface covered by other cubes or by the table or desk. 1. 2. volume = volume = visible surface area = visible surface area = 3. 4. 5. volume = volume = visible surface area = visible surface area = visible surface area = 3 in. 4 in. 6. Find the volume and the visible surface area of the figure at the right. 3 in. volume = 5 in. visible surface area = 3 in. 3 in. 8 in. Chapter 12 30 5 in. 4 in. Glencoe Geometry Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. volume = NAME DATE 12-5 PERIOD Study Guide and Intervention Volumes of Pyramids and Cones Volumes of Pyramids This figure shows a prism and a pyramid that have the same base and the same height. It is clear that the volume of the pyramid is less than the volume of the prism. More specifically, the volume of the pyramid is one-third of the volume of the prism. Volume of a Pyramid If a pyramid has a volume of V cubic units, a height of h units, 1 and a base with an area of B square units, then V = − Bh. Example Find the volume of the square pyramid. 1 Bh V=− 3 1 =− (8)(8)10 3 3 10 ft Volume of a pyramid B = (8)(8), h = 10 8 ft 8 ft ≈ 213.3 Multiply. The volume is about 213.3 cubic feet. Exercises Find the volume of each pyramid. Round to the nearest tenth if necessary. 2. 10 ft 15 ft 6 ft 8 ft 12 ft 3. 10 ft 4. 12 cm 18 ft 8 cm regular hexagon 4 cm 5. 16 in. 6. 6 yd 8 yd 15 in. 5 yd 15 in. Chapter 12 6 ft Lesson 12-5 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 1. 31 Glencoe Geometry NAME DATE 12-5 PERIOD Study Guide and Intervention (continued) Volumes of Pyramids and Cones Volumes of Cones For a cone, the volume is one-third the product of the height and the area of the base. The base of a cone is a circle, so the area of the base is πr2. Volume of a Cone Example If a cone has a volume of V cubic units, a height of h units, 1 2 and the bases have a radius of r units, then V = − πr h. r 3 Find the volume of the cone. 1 2 πr h V=− 3 1 =− π(5)212 3 h 5 cm Volume of a cone 12 cm r = 5, h = 12 ≈ 314.2 Simplify. The volume of the cone is about 314.2 cubic centimeters. Exercises Find the volume of each cone. Round to the nearest tenth. 1. 10 ft 4. 12 in. 30 in. 20 ft Chapter 12 18 yd 45° 20 yd 6. 26 ft Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 3. 5. 8 ft 2. 10 cm 6 cm 45° 16 cm 32 Glencoe Geometry NAME DATE 12-5 PERIOD Skills Practice Volumes of Pyramids and Cones Find the volume of each pyramid or cone. Round to the nearest tenth if necessary. 1. 2. 8 cm 8 ft 5 ft 3. 12 m 4. 14 in. 25 m 8 in. 10 in. 5. 6. 14 yd 18 mm 66° 25 yd Find the volume of each oblique pyramid or cone. Round to the nearest tenth if necessary. 7. 8. 6 cm 12 cm 6 ft 4 ft 4 ft Lesson 12-5 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 4 cm 7 cm 5 ft Chapter 12 33 Glencoe Geometry NAME DATE 12-5 PERIOD Practice Volumes of Pyramids and Cones Find the volume of each pyramid or cone. Round to the nearest tenth if necessary. 1. 2. 23 cm 13 yd 9.2 yd 9.2 yd 12.5 cm 25 cm 3. 9 ft 4. 19 ft 5. 12 mm 52° 6. 11 ft 6 in. 37 ft 6 in. 7. CONSTRUCTION Mr. Ganty built a conical storage shed. The base of the shed is 4 meters in diameter and the height of the shed is 3.8 meters. What is the volume of the shed? 8. HISTORY The start of the pyramid age began with King Zoser’s pyramid, erected in the 27th century B.C. In its original state, it stood 62 meters high with a rectangular base that measured 140 meters by 118 meters. Find the volume of the original pyramid. Chapter 12 34 Glencoe Geometry Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 11 in. NAME 12-5 DATE PERIOD Word Problem Practice Volumes of Pyramids and Cones 1. ICE CREAM DISHES The part of a dish designed for ice cream is shaped like an upside-down cone. The base of the cone has a radius of 2 inches and the height is 1.2 inches. 4. SCULPTING A sculptor wants to remove stone from a cylindrical block 3 feet high and turn it into a cone. The diameter of the base of the cone and cylinder is 2 feet. What is the volume of the cone? Round your answer to the nearest hundredth. What is the volume of the stone that the sculptor must remove? Round your answer to the nearest hundredth. 5. STAGES A stage has the form of a square pyramid with the top sliced off along a plane parallel to the base. The side length of the top square is 12 feet and the side length of the bottom square is 16 feet. The height of the stage is 3 feet. 18 yd 30 yd What is the volume of the greenhouse? 12 feet 3 feet 16 feet 3. TEEPEE Caitlyn made a teepee for a class project. Her teepee had a diameter of 6 feet. The angle the side of the teepee made with the ground was 65°. a. What is the volume of the entire square pyramid that the stage is part of? b. What is the volume of the top of the pyramid that is removed to get the stage? 65˚ c. What is the volume of the stage? What was the volume of the teepee? Round your answer to the nearest hundredth. Chapter 12 35 Glencoe Geometry Lesson 12-5 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 2. GREENHOUSES A greenhouse has the shape of a square pyramid. The base has a side length of 30 yards. The height of the greenhouse is 18 yards. NAME 12-5 DATE PERIOD Enrichment Frustums A frustum is a figure formed when a plane intersects a pyramid or cone so that the plane is parallel to the solid’s base. The frustum is the part of the solid between the plane and the base. To find the volume of a frustum, the areas of both bases must be calculated and used in the formula. 1 V=− h(B1 + B2 + √ B1B2 ), 3 where h = height (perpendicular distance between the bases), B1 = area of top base, and B2 = area of bottom base. Describe the shape of the bases of each frustum. Then find the volume. Round to the nearest tenth. 13 cm 1. 2. 3 in. 6 cm 7.5 in. 5 cm 19.5 cm 3. 3m 2.25 m 4.5 m 4. 7 ft 8m 5m 6m 12 ft 13 ft 12 m Chapter 12 36 Glencoe Geometry Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 4.5 in. 9 cm NAME DATE 12-6 PERIOD Study Guide and Intervention Surface Areas of Spheres You can think of the surface area of a sphere as the total area of all of the nonoverlapping strips it would take to cover the sphere. If r is the radius of the sphere, then the area of a great circle of the sphere is πr2. The total surface area of the sphere is four times the area of a great circle. Surface Area of a Sphere r If a sphere has a surface area of S square units and a radius of r units, then S = 4πr2. Example Find the surface area of a sphere to the nearest tenth if the radius of the sphere is 6 centimeters. S = 4πr2 = 4π(6)2 ≈ 452.4 Surface area of a sphere r=6 6 cm Simplify. The surface area is 452.4 square centimeters. Exercises Find the surface area of each sphere or hemisphere. Round to the nearest tenth. 1. 2. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 5m 7 in 3. 4. 3 ft 9 cm 5. sphere: circumference of great circle = π cm 6. hemisphere: area of great circle ≈ 4π ft2 Chapter 12 37 Glencoe Geometry Lesson 12-6 Surface Areas and Volumes of Spheres NAME DATE 12-6 PERIOD Study Guide and Intervention (continued) Surface Areas and Volumes of Spheres Volumes of Spheres A sphere has one basic measurement, the length of its radius. If you know the length of the radius of a sphere, you can calculate its volume. r Volume of a Sphere 4 3 If a sphere has a volume of V cubic units and a radius of r units, then V = − πr . Example Find the volume of a sphere with radius 8 centimeters. 4 3 πr V=− 3 4 = − π (8)3 3 3 8 cm Volume of a sphere r=8 ≈ 2144.7 Simplify. The volume is about 2144.7 cubic centimeters. Exercises Find the volume of each sphere or hemisphere. Round to the nearest tenth. 2. 1. 3. 6 in. 16 in. 5 ft Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 4. hemisphere: radius 5 in. 5. sphere: circumference of great circle ≈ 25 ft 6. hemisphere: area of great circle ≈ 50 m2 Chapter 12 38 Glencoe Geometry NAME 12-6 DATE PERIOD Skills Practice Find the surface area of each sphere or hemisphere. Round to the nearest tenth. 1. 2. 32 m 7 in. 3. hemisphere: radius of great circle = 8 yd 4. sphere: area of great circle ≈ 28.6 in2 Find the volume of each sphere or hemisphere. Round to the nearest tenth. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 5. 6. 94.8 ft 16.2 cm 7. hemisphere: diameter = 48 yd 8. sphere: circumference of a great circle ≈ 26 m 9. sphere: diameter = 10 in. Chapter 12 39 Glencoe Geometry Lesson 12-6 Surface Areas and Volumes of Spheres NAME DATE 12-6 PERIOD Practice Surface Areas and Volumes of Spheres Find the surface area of each sphere or hemisphere. Round to the nearest tenth. 1. 2. 6.5 cm 89 ft 3. hemisphere: radius of great circle = 8.4 in. 4. sphere: area of great circle ≈ 29.8 m2 Find the volume of each sphere or hemisphere. Round to the nearest tenth. 5. 6. 32 m Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 12.32 ft 7. hemisphere: diameter = 18 mm 8. sphere: circumference ≈ 36 yd 9. sphere: radius = 12.4 in. Chapter 12 40 Glencoe Geometry NAME 12-6 DATE PERIOD Word Problem Practice 1. ORANGES Mandy cuts a spherical orange in half along a great circle. If the radius of the orange is 2 inches, what is the area of the cross section that Mandy cut? Round your answer to the nearest hundredth. 4. THE ATMOSPHERE About 99% of Earth’s atmosphere is contained in a 31-kilometer thick layer that enwraps the planet. The Earth itself is almost a sphere with radius 6378 kilometers. What is the ratio of the volume of the atmosphere to the volume of Earth? Round your answer to the nearest thousandth. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 2. BILLIARDS A billiard ball set consists 1 inches in of 16 spheres, each 2 − 4 diameter. What is the total volume of a complete set of billiard balls? Round your answer to the nearest thousandth of a cubic inch. 5. CUBES Marcus builds a sphere inside of a cube. The sphere fits snugly inside the cube so that the sphere touches the cube at one point on each side. The side length of the cube is 2 inches. 3. MOONS OF SATURN The planet Saturn has several moons. These can be modeled accurately by spheres. Saturn’s largest moon Titan has a radius of about 2575 kilometers. What is the approximate surface area of Titan? Round your answer to the nearest tenth. a. What is the surface area of the cube? b. What is the surface area of the sphere? Round your answers to the nearest hundredth. c. What is the ratio of the surface area of the cube to the surface area of the sphere? Round your answer to the nearest hundredth. Chapter 12 41 Glencoe Geometry Lesson 12-6 Surface Areas and Volumes of Spheres NAME DATE 12-6 PERIOD Enrichment Spheres and Density The density of a metal is a ratio of its mass to its volume. For example, the mass of aluminum is 2.7 grams per cubic centimeter. Here is a list of several metals and their densities. 2.7 g/cm3 19.32 g/cm3 11.35 g/cm3 10.50 g/cm3 Aluminum Gold Lead Silver Copper Iron Platinum 8.96 g/cm3 7.874 g/cm3 21.45 g/cm3 To calculate the mass of a piece of metal, multiply volume by density. Example Find the mass of a silver ball that is 0.8 cm in diameter. M=D·V 4 π(0.4)3 = 10.5 · − 3 ≈ 10.5(0.27) ≈ 2.81 The mass is about 2.81 grams. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Exercises Find the mass of each metal ball described. Assume the balls are spherical. Round your answers to the nearest tenth. 1. a copper ball 1.2 cm in diameter 2. a gold ball 0.6 cm in diameter 3. an aluminum ball with radius 3 cm 4. a platinum ball with radius 0.7 cm Solve. Assume the balls are spherical. Round your answers to the nearest tenth. 5. A lead ball weighs 326 grams. Find the radius of the ball to the nearest tenth of a centimeter. 6. An iron ball weighs 804 grams. Find the diameter of the ball to the nearest tenth of a centimeter. 7. A silver ball and a copper ball each have a diameter of 3.5 centimeters. Which weighs more? How much more? 8. An aluminum ball and a lead ball each have a radius of 1.2 centimeters. Which weighs more? How much more? Chapter 12 42 Glencoe Geometry NAME DATE 12-7 PERIOD Study Guide and Intervention Spherical Geometry Geometry On A Sphere Up to now, we have been studying Euclidean geometry, where a plane is a flat surface made up of points that extends infinitely in all directions. In spherical geometry, a plane is the surface of a sphere. Name each of the following on sphere K. " $ a. two lines containing the point F # & and BH are lines on sphere K that contain the point F EG % b. a line segment containing the point J −− ID is a segment on sphere K that contains the point J ' K ( ) c. a triangle * + AHI is a triangle on sphere K Exercises Name two lines containing point Z, a segment containing point R, and a triangle in each of the following spheres. 1. 2. 5 # 4 $ Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 6 : ; F 9 ; 8 % " 3 ' 7 3 ( M & Determine whether figure u on each of the spheres shown is a line in spherical geometry. 3. 4. V V 5. GEOGRAPHY Lines of latitude run horizontally across the surface of Earth. Are there any lines of latitude that are great circles? Explain. Chapter 12 43 Glencoe Geometry Lesson 12-7 Example NAME 12-7 DATE PERIOD Study Guide and Intervention (continued) Spherical Geometry Comparing Euclidean and Spherical Geometries Some postulates and properties of Euclidean geometry are true in spherical geometry. Others are not true or are true only under certain circumstances. Example Tell whether the following postulate or property of plane Euclidean geometry has a corresponding statement in spherical geometry. If so, write the corresponding statement. If not, explain your reasoning. Given any line, there are an infinite number of parallel lines. On the sphere to the right, if we are given line m we see that it goes through the poles of the sphere. If we try to make any other line on the sphere, it would intersect line m at exactly 2 points. This property is not true in spherical geometry. A corresponding statement in spherical geometry would be: “Given any line, there are no parallel lines.” N Exercises Tell whether the following postulate or property of plane Euclidean geometry has a corresponding statement in spherical geometry. If so, write the corresponding statement. If not, explain your reasoning. 2. Given a line and a point on the line, there is only one perpendicular line going through that point. 3. Given two parallel lines and a transversal, alternate interior angles are congruent. 4. If two lines are perpendicular to a third line, they are parallel. 5. Three noncollinear points determine a triangle. 6. A largest angle of a triangle is opposite the largest side. Chapter 12 44 Glencoe Geometry Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 1. If two nonidentical lines intersect at a point, they do not intersect again. NAME DATE 12-7 PERIOD Skills Practice Spherical Geometry Name two lines containing point K, a segment containing point T, and a triangle in each of the following spheres. 2. ' C , ) # L ( " 6 5 $ Lesson 12-7 , 1. * 5 & 4 % Determine whether figure u on each of the spheres shown is a line in spherical geometry. 3. V 4. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. V basketball Tell whether the following postulate or property of plane Euclidean geometry has a corresponding statement in spherical geometry. If so, write the corresponding statement. If not, explain your reasoning. 5. If two lines form vertical angles, then the angles are equal in measure. 6. If two lines meet a third line at the same angle, those lines are parallel. 7. Two lines meet at two 90° angles or they meet at angles whose sum is 180°. 8. Three non-parallel lines divide the plane into 7 separate parts. Chapter 12 45 Glencoe Geometry NAME DATE 12-7 PERIOD Practice Spherical Geometry Name two lines containing point K, a segment containing point T, and a triangle in each of the following spheres. 1. , , 2. # " % ; ' 5 $ 9 L 5 M & : Determine whether figure u on each of the spheres shown is a line in spherical geometry. 3. 4. V V tennis ball 6. The sum of the angles of a triangle is 180°. 7. Given a line and a point not on the line, there is exactly one line that goes through the point and is perpendicular to the line. 8. All equilateral triangles are similar. 9. AIRPLANES When flying an airplane from New York to Seattle, what is the shortest route: flying directly west, or flying north across Canada? Explain. Chapter 12 46 Glencoe Geometry Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Tell whether the following postulate or property of plane Euclidean geometry has a corresponding statement in spherical geometry. If so, write the corresponding statement. If not, explain your reasoning. 5. A triangle can have at most one obtuse angle. NAME DATE 12-7 PERIOD Word Problem Practice 1. PAINTING Consider painting quadrilateral ABCD on the beach ball with radius 1 ft. What is the surface area you would need to paint? 5. GEOGRAPHY Latitude and longitude lines are imaginary lines on Earth. The lines of latitude are horizontal concentric circles that help to define the distance a place is from the equator. Lines of latitude are measured in degrees. The equator is 0°. The north pole is 90° north latitude. The lines of longitude are great circles that help to define the distance a place is from the Prime Meridan, which is located in England and considered the longitude of 0°. A D B Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. C 2. EARTH The Equator and the Prime Meridian are perpendicular great circles that divide Earth into North, South and East, West hemispheres. If Earth has a surface area of 197,000,000 square miles, what is the surface area of the North-East section of Earth? a. The mean radius of Earth is 3963 miles. Atlanta, Georgia, has coordinates (33°N, 84°W) and Cincinnati, Ohio, has coordinates (39°N, 84°W). Estimate the distance between Atlanta and Cincinnati to the nearest tenth. Source: NASA 3. OCEAN If the oceans cover 70% of Earth’s surface, what is the surface area of the oceans? Source: NASA b. Seattle, Washington, has coordinates (47°N, 122°W) and Portland, Oregon, has coordinates (45°N, 122°W). Estimate the distance between Portland and Seattle to the nearest tenth. 4. GEOMETRY Three nonidentical lines on the circle divide it into either 6 sections or 8 triangles. What condition is needed so that the three lines form 6 sections? Chapter 12 47 Glencoe Geometry Lesson 12-7 Spherical Geometry NAME 12-7 DATE PERIOD Enrichment Spherical Geometry Projections 180˚ W 90˚ W When making maps of Earth, cartographers must show a sphere on a plane. To do this they have to use projections, a method of converting a sphere into a plane. But these projections have their limitations. The map on the right is a Mercator projection of Earth. On this map Greenland appears to be the same size as Africa. But Greenland has a land area of 2,166,086 square kilometers and Africa has a land area of 30,365,700 square kilometers. 0˚ 90˚ E 180˚ E 60˚ N 40˚ N 20˚ N 0˚ 20˚ S 40˚ S 60˚ S The map on the right is a Lambert projection. When a pilot draws a straight line between two points on this map the line shows true bearing, or relative direction to the North Pole. However, the bottom area of this map distorts distances. 2. Does each square on the Mercator projection have the same surface area? Explain. 3. Does each square on the Lambert projection have the same surface area? Explain. 4. The Mercator projection uses a cylinder to map Earth, while the Lambert projection uses a cone to map Earth. What other shapes do you think could be used to map Earth? Chapter 12 48 Glencoe Geometry Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 1. When would it be useful to use a Mercator projection of Earth? NAME DATE 12-8 PERIOD Study Guide and Intervention Congruent and Similar Solids Identify Congruent or Similar Solids Similar solids have exactly the same shape but not necessarily the same size. Two solids are similar if they are the same shape and the ratios of their corresponding linear measures are equal. All spheres are similar and all cubes are similar. Congruent solids have exactly the same shape and the same size. Congruent solids are similar solids with a scale factor of 1:1. Congruent solids have the following characteristics: Corresponding angles are congruent Corresponding edges are congruent Corresponding faces are congruent Volumes are equal Example Determine whether the pair of solids is similar, congruent, or neither. If the solids are similar, state the scale factor. 3 1 ratio of width: − =− 4 1 ratio of length: − =− 5 1 =− ratio of hypotenuse: − 4 1 ratio of height: − =− 6 2 10 8 2 8 2 6 in. 8 in. 8 in. 4 in. 3 in. 4 in. 2 10 in. 5 in. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. The ratios of the corresponding sides are equal, so the triangular prisms are similar. The scale factor is 1:2. Since the scale factor is not 1:1, the solids are not congruent. Exercises Determine whether the pair of solids is similar, congruent, or neither. If the solids are similar, state the scale factor. 1. 2. 5 cm 4.2 in. 12.3 in. 12.3 in. 4.2 in. 1 cm 2 cm 10 cm 3. 4. 2m 8 in. 4m 2m 1m 1m 3m 4 in. Chapter 12 49 Glencoe Geometry Lesson 12-8 • • • • NAME DATE 12-8 PERIOD Study Guide and Intervention (continued) Congruent and Similar Solids Properties of Congruent or Similar Solids When pairs of solids are congruent or similar, certain properties are known. If two similar solids have a scale factor of a:b then, • the ratio of their surface areas is a2:b2. • the ratio of their volumes is a3:b3. Example Two spheres have radii of 2 feet and 6 feet. What is the ratio of the volume of the small sphere to the volume of the large sphere? First, find the scale factor. radius of the small sphere radius of the large sphere 6 ft 2 1 −− = − or − 6 2 ft 3 1 . The scale factor is − 3 3 (1)3 (3) a 1 − = −3 or − 3 b 27 So, the ratio of the volumes is 1:27. Exercises 2. Two similar cones have heights of 3 feet and 12 feet. What is the ratio of the volume of the small cone to the volume of the large cone? 3. Two similar triangular prisms have volumes of 27 square meters and 64 square meters. What is the ratio of the surface area of the small prism to the surface area of the large prism? 4. COMPUTERS A small rectangular laptop has a width of 10 inches and an area of 80 square inches. A larger and similar laptop has a width of 15 inches. What is the length of the larger laptop? 5. CONSTRUCTION A building company uses two similar sizes of pipes. The smaller size has a radius of 1 inch and length of 8 inches. The larger size has a radius of 2.5 inches What is the volume of the larger pipes? Chapter 12 50 Glencoe Geometry Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 1. Two cubes have side lengths of 3 inches and 8 inches. What is the ratio of the surface area of the small cube to the surface area of the large cube? NAME DATE 12-8 PERIOD Skills Practice Congruent and Similar Solids Determine whether each pair of solids is similar, congruent, or neither. If the solids are similar, state the scale factor. 1. 2. 9 cm 12 cm 9 cm 3 cm 12 cm 4 cm 6 cm 6 cm 3. 4. 5m 3 ft 10 m 1 ft 3 ft Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 8 cm 1 ft 3 ft 9 ft 5. Two similar pyramids have heights of 4 inches and 7 inches What is the ratio of the volume of the small pyramid to the volume of the large pyramid? 6. Two similar cylinders have surface areas of 40π square feet and 90π square feet. What is the ratio of the height of the large cylinder to the height of the small cylinder? 7. COOKING Two stockpots are similar cylinders. The smaller stockpot has a height of 10 inches and a radius of 2.5 inches. The larger stockpot has a height of 16 inches. What is the volume of the larger stockpot? Round to the nearest tenth. Chapter 12 51 Glencoe Geometry Lesson 12-8 2 cm NAME 12-8 DATE PERIOD Practice Congruent and Similar Solids Determine whether the pair of solids is similar, congruent, or neither. If the solids are similar, state the scale factor. 1. 2. 10 cm 18 cm 5 cm 24 cm 6 cm 24 cm 12 cm 8 cm 3. 1 m 5m 4m 1m 5m 4. 10 cm 5 cm 4m 10 cm 5 cm 3m 3m 2 cm 1.5 cm 6. Two similar ice cream cones are made of a half sphere on top and a cone on bottom. They have radii of 1 inch and 1.75 inches respectively. What is the ratio of the volume of the small ice cream cone to the volume of the large ice cream cone? Round to the nearest tenth. 7. ARCITHECTURE Architects make scale models of buildings to present their ideas to clients. If an architect wants to make a 1:50 scale model of a 4000 square foot house, how many square feet will the model have? Chapter 12 52 Glencoe Geometry Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 5. Two cubes have surface areas of 72 square feet and 98 square feet. What is the ratio of the volume of the small cube to the volume of the large cube? NAME DATE 12-8 PERIOD Word Problem Practice Congruent and Similar Solids 1. COOKING A cylindrical pot is 4.5 inches tall and has a radius of 4 inches. How tall would a similar pot be if its radius is 6 inches? 4. PLANETS Earth has a surface area of about 196,937,500 square miles. Mars has a surface area of about 89,500,000 square miles. What is the ratio of the radius of Earth to the radius of Mars? Round to the nearest tenth. Source: NASA 2. MANUFACTURING Boxes, Inc. wants to make the two boxes below. How long does the second box need to be so that they are similar? 25 cm 5. BASEBALL Major League Baseball or MLB, rules state that baseballs must have a circumference of 9 inches. The National Softball Association, or NSA, rules state that softballs must have a circumference not exceeding 12 inches. 15 cm Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 15 cm 25 cm Source: MLB, NSA a. Find the ratio of the circumference of MLB baseballs to the circumference of NSA softballs. 3. FARMING A farmer has two similar cylindrical grain silos. The smaller silo is 25 feet tall and the larger silo is 40 feet tall. If the smaller silo can hold 1500 cubic feet of grain, how much can the larger silo hold? Chapter 12 b. Find the ratio of the volume of MLB baseballs to the volume of NSA softballs. Round to the nearest tenth. 53 Glencoe Geometry Lesson 12-8 24 cm NAME 12-8 DATE PERIOD Enrichment Doubling Sizes Consider what happens to surface area when the sides of a figure are doubled. The sides of the large cube are twice the size of the sides of the small cube. 5 in. 1. How long are the edges of the large cube? 2. What is the surface area of the small cube? 3. What is the surface area of the large cube? 4. The surface area of the large cube is how many times greater than that of the small cube? The radius of the large sphere at the right is twice the radius of the small sphere. 3m 5. What is the surface area of the small sphere? 6. What is the surface area of the large sphere? 7. The surface area of the large sphere is how many times greater than the surface area of the small sphere? Now consider how doubling the dimensions affects the volume of a cube. The sides of the large cube are twice the size of the sides of the small cube. 9. How long are the edges of the large cube? 5 in. 10. What is the volume of the small cube? 11. What is the volume of the large cube? 12. The volume of the large cube is how many times greater than that of the small cube? The large sphere at the right has twice the radius of the small sphere. 3m 13. What is the volume of the small sphere? 14. What is the volume of the large sphere? 15. The volume of the large sphere is how many times greater than the volume of the small sphere? 16. It appears that if the dimensions of a solid are doubled, the volume is multiplied by . Chapter 12 54 Glencoe Geometry Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 8. It appears that if the dimensions of a solid are doubled, the surface area is multiplied by . NAME DATE 12 PERIOD Student Recording Sheet Assessment Use this recording sheet with pages 894– 895 of the Student Edition. Multiple Choice Read each question. Then fill in the correct answer. 1. A B C D 3. A B C D 5. A B C D 2. F G H J 4. F G H J 6. F G H J Short Response/Gridded Response Record your answer in the blank. For gridded response questions, also enter your answer in the grid by writing each number or symbol in a box. Then fill in the corresponding circle for that number or symbol. 7. ———————— Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 8. ———————— 9. ———————— (grid in) 10. ———————— 11. ———————— (grid in) 11. 9. . . . . . . . . . . 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 4 4 4 4 4 4 4 4 4 4 5 5 5 5 5 5 5 5 5 5 6 6 6 6 6 6 6 6 6 6 7 7 7 7 7 7 7 7 7 7 8 8 8 8 8 8 8 8 8 8 9 9 9 9 9 9 9 9 9 9 12. ———————— Extended Response Record your answers for Question 13 on the back of this paper. Chapter 12 55 Glencoe Geometry NAME DATE 12 PERIOD Rubric for Scoring Extended-Response General Scoring Guidelines • If a student gives only a correct numerical answer to a problem but does not show how he or she arrived at the answer, the student will be awarded only 1 credit. All extended response questions require the student to show work. • A fully correct answer for a multiple-part question requires correct responses for all parts of the question. For example, if a question has three parts, the correct response to one or two parts of the question that required work to be shown is not considered a fully correct response. • Students who use trial and error to solve a problem must show their method. Merely showing that the answer checks or is correct is not considered a complete response for full credit. Exercise 13 Rubric Specific Criteria 4 A correct solution that is supported by well-developed, accurate explanations. The scale factor of the prisms, and the correct volumes of the prisms are provided. The student displays an understanding of how volume changes based upon changing dimensions by correctly answering parts c and d. 3 A generally correct solution, but may contain minor flaws in reasoning or computation. 2 A partially correct interpretation and/or solution to the problem. 1 A correct solution with no evidence or explanation. 0 An incorrect solution indicating no mathematical understanding of the concept or task, or no solution is given. Chapter 12 56 Glencoe Geometry Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Score NAME 12 DATE PERIOD Chapter 12 Quiz 1 SCORE 1. Given the corner view of a figure, draw the left view. 1. 2. A cylinder has a lateral area of 120π square meters, and a height of 7 meters. Find the radius. Round to the nearest tenth. 2. 3. Find the lateral area of the hexagonal prism. 3. 10 Assessment (Lessons 12-1 and 12-2) 2 4. Find the surface area of a rectangular prism with a length and width of 6 centimeters and a height of 12 centimeters. 4. 3.5 5. MULTIPLE CHOICE Find the surface area of the prism to the nearest hundredth. A 30.50 B 54.00 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. C 49.45 3 5. D 52.44 NAME 12 5 DATE PERIOD Chapter 12 Quiz 2 SCORE (Lessons 12-3 and 12-4) 1. Find the surface area of the solid figure at the right to the nearest tenth. 6 in. 9 in. 1. 9 in. For Questions 2 and 3, use a right circular cone with a radius of 5 feet and a slant height of 12 feet. Round to the nearest tenth. 2. Find the lateral area. 2. 3. Find the surface area. 3. 4. A rectangular prism has a length of 16 feet, a width of 9 feet, and a height of 8 feet. Find the volume of the prism. 4. 5. A cylinder has a diameter of 20 inches and a height of 9 inches. Find the volume of the cylinder, round to the nearest tenth. 5. Chapter 12 57 Glencoe Geometry NAME 12 DATE PERIOD Chapter 12 Quiz 3 SCORE (Lessons 12-5 and 12-6) 1. A pyramid has a height of 18 centimeters and a base with an area of 26 square centimeters. Find the volume. 1. 2. Find the volume of the cone. Round to the nearest tenth. 2. 16 cm 17 cm 3. A hemisphere has a base with an area that is 25π square centimeters. Find the volume of the hemisphere. Round to the nearest tenth. 3. 4. A sphere has a great circle with a circumference of 8π meters. What is the surface area of the sphere? 4. 5. MULTIPLE CHOICE A sphere has a radius that is 15.6 inches long. Find the volume of the sphere. Round to the nearest tenth. A 1019.4 in3 C 15,902 in3 3 B 7951.2 in D 47,702.2 in3 5. NAME 12 DATE PERIOD Chapter 12 Quiz 4 SCORE 1. Name two lines containing point Z, a segment containing point R, and a triangle in the sphere F. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. (Lessons 12-7 and 12-8) 5 6 4 8 ; 1. : 3 9 F 7 2. Do all lines have an infinite number of points in spherical geometry? If not, explain your reasoning. 2. 3. Determine whether the pair of solids is similar, congruent, or neither. If the solids are similar, state the scale factor. 3. 1m 0.5 m 4. Two similar prisms have heights of 12 feet and 20 feet. What is the ratio of the volume of the small prism to the volume of the large prism? 4. 5. Two cubes have surface areas of 81 square inches and 144 square inches. What is the ratio of the volume of the small cube to the volume of the large cube? 5. Chapter 12 58 Glencoe Geometry NAME 12 DATE PERIOD Chapter 12 Mid-Chapter Test SCORE Part I Write the letter for the correct answer in the blank at the right of each question. 1. A cylinder is standing on one of its bases. It is sliced by a plane horizontally. What is the shape of the cross section? A triangle C circle B square D rectangle 1. 2. Choose the correct formula for the surface area of a cone. 1 F S = Ph + 2B H S=− P + B 2 G S = πr + πr2 2. J S = πr + 2πr 3. The surface area of a prism is 120 square centimeters and the area of each base is 32 square centimeters. Find the lateral area of the prism. A 184 cm2 B 152 cm2 C 86 cm2 D 56 cm2 3. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. For Questions 4 and 5, refer to the solid figure. Round to the nearest tenth. 46.2 ft 4. Find the lateral area. F 9289.1 ft2 G 9434.2 ft2 H 10,965.4 ft2 J 12,641.8 ft2 5. Find the surface area. A 9289.1 ft2 B 9434.2 ft2 C 10,965.4 ft2 64 ft 4. D 12,641.8 ft2 5. Part II 6. Draw the top view of this orthogonal drawing. 6. For Questions 7 and 8, refer to the regular hexagonal prism. 7. Sketch the cross section from a vertical slice of the figure. 2 7. 6 8. Find the surface area. Round to the nearest tenth. 8. 9. A barrel in the shape of a right cylinder has a diameter of 18 inches and a height of 42 inches. Find the surface area of the barrel. 9. 10. Find the lateral area of the solid. Round to the nearest tenth. 4 in. 10. 6 in. Chapter 12 59 Glencoe Geometry Assessment (Lessons 12-1 through 12-4) NAME DATE 12 PERIOD Chapter 12 Vocabulary Test altitude axis base edges composite solid congruent solid cross section Euclidean geometry great circle SCORE regular pyramidright cone right cylinder right prism similar solids slant height spherical geometry topographical map isometric view lateral area lateral edge lateral face non-Euclidean geometry oblique cone oblique cylinder oblique prism Choose from the terms above to complete each sentence. 1. The height of each lateral face of a regular pyramid is called ? a(n) . ? 2. have the same shape but not the same size. 3. If the axis of a cylindrical is also the altitude, then the ? cylinder is called a(n) . 4. ? is the measure of the amount of space that a figure encloses. 1. 2. 3. 4. Choose the correct term to complete each sentence. 5. 6. Two solids that have the same shape and the same size are called (congruent solids, composite solids). 6. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 5. The segment whose endpoints are the centers of the circular bases of a cylinder is the (axis, hemisphere) State whether each sentence is true or false. If false, replace the underlined word or phrase to make a true sentence. 7. A polyhedron that has all but one face intersecting at one point is a prism. 7. 8. A cross section is the intersection of a plane and a solid figure. 8. 9. A hexagonal prism has a six lateral faces. 9. 10. A cone with an axis that is not an altitude is a right cone. 10. Define each term in your own words. 11. lateral area 11. 12. right prism 12. Chapter 12 60 Glencoe Geometry 12 DATE PERIOD Chapter 12 Test, Form 1 SCORE Write the letter for the correct answer in the blank at the right of each question. 1. Which of these is part of an orthographic drawing? A a perspective view C a two-dimensional top view B a corner view D a three-dimensional view For Questions 2–4, refer to the figure. E 2. Identify this solid figure. F square pyramid G square prism H J triangular pyramid triangular prism 3. Name the base. A ABE C CDE B ABCD 4. The shape of a vertical cross section of a cone is a F circle G triangle H square 5. Find the surface area of the cube. A 9 in2 B 27 in2 C D 1. C B A D 2. 3. D E ? J . trapezoid 4. 3 in. 36 in2 54 in2 3 in. 5. 3 in. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. For Questions 6 and 7, refer to the figure. 6. Find the lateral area. Round to the nearest tenth. F 75.4 ft2 H 50.3 ft2 G 62.8 ft2 J 25.1 ft2 2 ft 4 ft 7. Find the surface area. Round to the nearest tenth. A 75.4 ft2 B 62.8 ft2 C 50.3 ft2 6. 7. D 25.1 ft2 For Questions 8 and 9, refer to the figure. 8. Find the lateral area. F 108 cm2 G 144 cm2 9. Find the surface area. A 108 cm2 B 144 cm2 H J 9 cm 162 cm2 324 cm2 8. 6 cm 6 cm C 162 cm2 D 324 cm2 9. 50 10. Find the surface area to the nearest tenth. F 546.6 units2 H 1017.9 units2 2 G 989.6 units J 1046.2 units2 5 6 10. 11. The radius of a cone is 17 inches long and the slant height is 20 inches. Find the surface area to the nearest tenth. A 18,158.4 in2 B 1976.1 in2 C 1068.1 in2 D 340 in2 Chapter 12 61 11. Glencoe Geometry Assessment NAME NAME 12 DATE PERIOD Chapter 12 Test, Form 1 (continued) 12. The area of the base of a prism is 96 square centimeters and the height is 9 centimeters. Find the volume of the prism. F 288 cm3 G 864 cm3 H 932 cm3 J 7776 cm3 12. 13. The volume of a cylinder is 62.8 cubic meters and the radius is 2 meters. Find the height of the cylinder. Round to the nearest meter. A 20 m B 10 m C 8m D 5m 13. 14. A pyramid has a height of 10 inches and a base with an area of 21 square inches. Find the volume of the pyramid. F 210 in3 G 105 in3 H 70 in3 J 35 in3 14. 6 in. 15. Find the volume of the oblique cone. Round to the nearest tenth. A 1206.4 in3 C 301.6 in3 B 402.1 in3 D 100.5 in3 10 in. 15. 16. 17. A sphere has a volume that is 36π cubic meters. Find the radius of the sphere. A 2m B 3m C 6m D 12 m 17. 18. Which of the following postulates or properties of spherical geometry are true? F A line has an infinite number of lines parallel to it. G No two lines are parallel. H Alternate interior angles formed by two parallel lines and a transversal are equal in measure. J Four noncollinear points form two parallel lines. 18. 19. Which of the following describes the two spheres? A congruent C both congruent and similar B similar D neither congruent nor similar 9 ft 6 ft 19. 20. The ratio of the side lengths of two cubes is 3:7. Find the ratio of their volumes. F 3:7 G 9:21 H 9:49 J 27:343 8 ft Bonus Find the amount of glass needed to cover the sides of the greenhouse shown. The bottom, front, and back are not glass. Chapter 12 20. 8 ft 9 ft 9 ft 30 ft B: 15 ft 62 Glencoe Geometry Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 16. The diameter of a sphere is 42 centimeters. Find the surface area to the nearest tenth. F 5541.8 cm2 G 2770.9 cm2 H 2167.1 cm2 J 527.8 cm2 DATE 12 Chapter 12 Test, Form 2A PERIOD SCORE Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Write the letter for the correct answer in the blank at the right of each question. 1. What do the dark segments represent in an orthographic drawing? A changes in color C designs on the surface B where paper should be folded D different heights in the surface 1. For Questions 2 and 3, refer to the figure. 2. Identify the figure. F pyramid H cone G prism J cylinder 2. X Y 3. Identify the shape of a horizontal cross section of the figure. A triangle B ellipse C rectangle D circle 3. 4. The lateral area of a cube is 36 square inches. How long is each edge? in. F √6 G 3 in. H 6 in. J 9 in. 4. 5. Find the surface area of the outside of the open box. A 1920 in2 C 752 in2 B 998 in2 D 400 in2 5. 8 in. 12 in. 20 in. For Questions 6 and 7, use a right cylinder with a radius of 3 inches and a height of 17 inches. Round to the nearest tenth. 6. Find the lateral area. F 320.4 in2 G 348.7 in2 H 377.0 in2 J 537.2 in2 6. 7. Find the surface area. A 320.4 in2 B 348.7 in2 7. C 377.0 in2 D 537.2 in2 For Questions 8 and 9, refer to the figure. 8. Find the lateral area. F 144 cm2 H 196 cm2 G 144 + 24 √ 3 cm2 J 288 cm2 12 cm 8. 4 cm 9. Find the surface area. A 144 cm2 B 144 + 24 √ 3 cm2 C 196 cm2 For Questions 10 and 11, refer to the figure. Round to the nearest tenth. D 288 cm2 12 in. 9. 2 in. 10. Find the lateral area. G 75.4 in2 F 44.0 in2 H 88.0 in2 J 100.5 in2 10. 11. Find the surface area. A 44.0 in2 B 75.4 in2 C 88.0 in2 D 100.5 in2 11. Chapter 12 63 Glencoe Geometry Assessment NAME NAME 12 DATE PERIOD Chapter 12 Test, Form 2A (continued) 12. The surface area of a cube is 96 square feet. Find the volume of the cube. F 4 ft3 G 16 ft3 H 64 ft3 J 256 ft3 12. 13. A cylinder whose height is 5 meters has a volume of 320π cubic meters. Find the radius of the cylinder. A 8m B 12.8 m C 64 m D 201 m 13. 14. A square pyramid has a height that is 8 centimeters long and a base with sides that are each 9 centimeters long. Find the volume of the pyramid. F 648 cm3 G 324 cm3 H 216 cm3 J 162 cm3 14. 15. Find the volume to the nearest tenth. A 3619.1 m3 C 14,476.5 m3 B 4825.5 m3 D 43,429.4 m3 15. 24 m 60° 16. Find the surface area to the nearest tenth. F 4536.5 m2 H 477.5 m2 2 G 2268.2 m J 238.8 m2 19 m D 9 in. 17. 18. The shortest distance between any two points in spherical geometry is F a straight line. G any circle. H a great circle. J a line through the sphere. 18. 19. Two square pyramids are similar. The sides of the bases are 4 inches and 12 inches. The height of the smaller pyramid is 6 inches. Find the height of the larger pyramid. A 24 in. B 18 in. C 16 in. D 14 in. 19. 20. The ratio of the radii of two similar cylinders is 3:5. The volume of the smaller cylinder is 54π cubic centimeters. Find the volume of the larger cylinder. F 90π cm3 G 150π cm3 H 250π cm3 J 540π cm3 20. 1 ft Bonus Find the surface area of the figure to the nearest tenth. B: 12 ft 4 ft Chapter 12 64 Glencoe Geometry Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 17. A sphere has a volume of 972π cubic inches. Find the radius of the sphere. A 2 in. B 3 in. C 6 in. 16. 12 DATE PERIOD Chapter 12 Test, Form 2B SCORE Write the letter for the correct answer in the blank at the right of each question. 1. Given the corner view of a figure, which is the top view? A B C D 1. For Questions 2 and 3, refer to the figure. 2. Identify the figure. F pyramid H cone G prism J cylinder Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 3. Identify the shape of a vertical cross section of the figure. A rectangle B circle C triangle M 2. N D parabola 3. 4. Find the lateral area of an equilateral triangular prism if the area of each lateral face is 10 square centimeters. F 10 √ 3 cm2 G 30 cm2 H 50 cm2 J 100 cm2 4. 5. The surface area of a rectangular prism is 190 square inches, the length is 10 inches, and the width 3 inches. Find the height. A 30 in. B 20 in. C 10 in. D 5 in. 5. For Questions 6–9, use a right cylinder with a radius of 5 centimeters and a height of 22 centimeters. Round to the nearest tenth. 6. Find the lateral area. F 848.2 cm2 G 769.7 cm2 H 691.2 cm2 J 345.6 cm2 6. 7. Find the surface area. A 848.2 cm2 B 769.7 cm2 C 691.2 cm2 D 345.6 cm2 7. 8. Find the volume. F 345.6 cm3 H 1727.9 cm3 J 2290.2 cm3 8. G 691.2 cm3 For Questions 9–11, refer to the figure. Round to the nearest tenth. 9. Find the lateral area. 8 cm 3 cm A 75.4 cm2 C 131.9 cm2 B 103.7 cm2 D 150.8 cm2 9. 10. Find the surface area. G 75.4 cm2 G 103.7 cm2 H 131.9 cm2 J 150.8 cm2 10. 11. Find the volume. A 50.3 cm3 C 209.7 cm3 J 226.2 cm3 11. Chapter 12 B 69.9 cm3 65 Glencoe Geometry Assessment NAME NAME 12 DATE PERIOD Chapter 12 Test, Form 2B (continued) 12. The lateral area of a cube is 324 square centimeters. Find the volume of the cube. G 81 cm3 H 729 cm3 J 972 cm3 F 9 cm3 12. 13. Find the volume of the solid. Round to the nearest tenth. A 31.4 in3 C 125.7 in3 B 41.9 in3 D 502.7 in3 13. 4 in. 10 in. 14. A right triangular pyramid has a 12-meter height and a base with legs that are 3 meters and 4 meters long. Find the volume of the triangular pyramid. F 144 m3 G 72 m3 H 48 m3 J 24 m3 14. 15. Find the volume of the cone. Round to the nearest tenth. A 41,224.0 m3 C 10,306.0 m3 B 20,612.0 m3 D 763.4 m3 27 m 15. 45° 16. The surface area of a sphere is 64π square centimeters. Find the radius. F 16 cm G 8 cm H 4 cm J 2 cm 16. 18. In spherical geometry, two lines must meet at least how many times? F zero times H two times G one time J an infinite number of times 18. 19. Find the scale factor between the two similar cones. A 3:8 C 1:2 B 1:3 D 1:4 19. 8 ft 16 ft 3 ft 6 ft 20. The ratio of the heights of two similar solids is 6:11. Find the ratio of their surface areas. F 6:11 G 36:121 H 216:1331 J 24:44 Bonus Find the surface area of the frustum of a square pyramid. 2 ft 4 ft 20. B: 3 ft Chapter 12 66 Glencoe Geometry Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 17. A sphere has a 48-centimeter diameter. Find the volume of the sphere. Round to the nearest tenth. A 463,246.7 cm3 B 57,905.8 cm3 C 28,952.9 cm3 D 7238.2 cm3 17. 12 DATE PERIOD Chapter 12 Test, Form 2C SCORE 1. Given the corner view of a figure, sketch the front view. Assessment NAME 1. 2. Name the faces of the solid. 2. T R Q P S 3. Sketch the shape of a horizonal cross section of the solid. 3. 4. Find the lateral area of a triangular prism with a height of 8 centimeters, and with bases having sides that measure 4 centimeters, 5 centimeters, and 6 centimeters. 4. 5. Find the surface area of the solid. 1 in. 5. 1 in. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 1 in. 6. Find the lateral area of a right cylinder with a diameter of 8.6 yards and a height of 19.4 yards. Round to the nearest tenth. 7. The surface area of a cylinder is 180π square inches and the height is 9 inches. Find the radius. 6. 7. For Questions 8 and 9, use a regular hexagonal pyramid with base edges of 10 inches and a slant height of 9 inches. 8. Find the lateral area. 8. 9. Find the surface area. 9. For Questions 10 and 11, use a right circular cone with a radius of 4 feet and a height of 3 feet. Round to the nearest tenth. 10. Find the lateral area. 10. 11. Find the surface area. 11. Chapter 12 67 Glencoe Geometry NAME 12 DATE PERIOD Chapter 12 Test, Form 2C (continued) 12. The volume of a rectangular prism is 120 cubic feet and the area of the base is 60 square feet. Find the length of a lateral edge of the prism. 12. 13. A cylinder has a 12-foot radius and a 17-foot height. Find the volume of the cylinder. Round to the nearest tenth. 13. 14. A regular hexagonal pyramid has a height that is 15 feet and a base 6 feet on each side. Find the volume of the pyramid. Round to the nearest tenth. 14. 8 ft 15. Find the volume of the oblique cone. Round to the nearest tenth. 16. Find the surface area of this hemisphere to the nearest tenth. 5 ft 30° 15. 11 in. 16. 17. A sphere has a diameter of 7.36 inches long. Find the volume of the sphere. Round to the nearest tenth. 17. 18. What best describes a line in spherical geometry? 18. 4 in. 10 in. 3 in. 9 in. 19. 20. The ratio of the heights of two similar prisms is 2:7. The surface area of the smaller prism is 50 square meters. Find the surface area of the larger prism. 20. Bonus The length of each side of a cube is 6 inches long. Find the surface area of a sphere inscribed in the cube. Round to the nearest tenth. B: Chapter 12 68 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 19. Determine whether these two cylinders are congruent, similar, or neither. Glencoe Geometry DATE 12 Chapter 12 Test, Form 2D 1. Given the corner view of a figure, sketch the back view. PERIOD SCORE Assessment NAME 1. J 2. Name the edges of the solid. 2. H G I 3. Sketch the shape of a horizonal cross section of the solid. 3. 4. Find the lateral area of a regular pentagonal prism if the perimeter of the base is 50 inches and the height is 15 inches. 4. 5. Find the surface area of the prism. 5. 6 ft Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 9 ft 5 ft 6. A right cylinder has a diameter of 23.6 meters and a height of 11.4 meters. Find the lateral area of the cylinder. Round to the nearest tenth. 6. 7. The surface area of a right cylinder is 252π square feet and the height is 11 feet. Find the radius of the cylinder. 7. For Questions 8 and 9, use a regular octagonal pyramid with base edges 9 feet long, slant height 15 feet, and a base with an apothem of 10.86 feet. 8. Find the lateral area. 8. 9. Find the surface area to the nearest tenth. 9. For Questions 10 and 11, use a cone with a radius of 5 centimeters and a height of 12 centimeters. Round to the nearest tenth. 10. Find the lateral area. 10. 11. Find the surface area. 11. Chapter 12 69 Glencoe Geometry NAME 12 DATE PERIOD Chapter 12 Test, Form 2D (continued) 12. An aquarium is 18 inches long, 8 inches wide, and 14 inches high. The water in it is 4 inches deep. Find the volume of the water. 12. 13. Find the volume of the cylinder. Round to the nearest tenth. 13. 25 cm 7 cm 14. A square pyramid has a height that is 51 inches and a base with sides that are each 11 inches long. Find the volume of the pyramid. 14. 4 cm 15. Find the volume of the oblique cone. Round to the nearest tenth. 6 cm 16. Find the surface area of the hemisphere. Round to the nearest tenth. 13 in. 17. A sphere has a radius that is 2.94 centimeters long. Find the volume of the sphere. Round to the nearest tenth. 15. 16. 17. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 18. Why do parallel lines not exist in spherical geometry? 19. Determine whether these cubes are congruent, similar, or neither. 18. 6 cm 8 cm 19. 20. The ratio of the heights of two similar pyramids is 2:5 and the volume of the smaller pyramid is 100 cubic feet. Find the volume of the larger pyramid. 20. Bonus The length of each side of a cube is 8 inches long. Find the surface area of a sphere inscribed in the cube. Round to the nearest tenth. B: Chapter 12 70 Glencoe Geometry 12 DATE PERIOD Chapter 12 Test, Form 3 1. Draw the back view of a figure given its orthographic drawing. top view left view SCORE front view right view Assessment NAME 1. 2. 2. Describe the cross section. 3. Find the surface area of the solid. Show the exact solution. √21 3 3. 3 4 8 4. Find the lateral area of a triangular prism with a right triangular base with legs that measure 2 feet and 3 feet and a height of 7 feet. Show the exact solution. 4. 5. Find the surface area of the prism. 5. 10 20 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 6 For Questions 6 and 7, use a right cylinder with a diameter of 96.4 feet and a height of 58.9 feet. Round to the nearest tenth. 6. Find the lateral area. 6. 7. Find the surface area. 7. For Questions 8 and 9, refer to the solid. Round to the nearest tenth if necessary. 13 in. 8. Find the lateral area. 8. 12 in. 9. Find the surface area to the nearest tenth. 9. For Questions 10 and 11, use a right circular cone with a radius of 7 inches and a height of 8 inches. Round to the nearest tenth. 10. Find the lateral area. 10. 11. Find the surface area. 11. Chapter 12 71 Glencoe Geometry NAME 12 DATE PERIOD Chapter 12 Test, Form 3 (continued) 10 cm 12. Find the volume of the solid. 12. 8 cm 12 cm 3 cm 2 cm 13. The volume of a cylinder is 96π cubic meters and the height is 13. 6 meters. Find the length of the diameter of this cylinder. 14. Sam is filling a rectangular pan with liquid from a cylindrical can. 2 in. The can is three-fourths full 8 in. of water. Determine whether all of the water will fit in the pan. Explain. 7 in. 3 in. 6 in. 14. 8 in. 2 in. 15. Find the volume of the solid. 15. 13 in. 16. 17. A cone is 9 centimeters deep and 4 centimeters across the top. A single scoop of ice cream, 4 centimeters in diameter, is placed on top of the cone. If the ice cream melts into the cone, determine whether the melted ice cream will fit in the cone. Explain. 17. 18. Is the angle sum of a triangle in spherical geometry always 180°? If not give an example. 18. 19. Determine whether these two pyramids are congruent, similar, or neither. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 16. Write a formula for the surface area of a hemisphere in terms of π and the radius r. 4m 5m 5m 6.4 m 8m 8m 5m 19. 8m 20. The ratio of the volumes of two similar solids is 1:2. Find the ratio of their surface areas. 20. 6 ft Bonus Find the surface area of the solid to the nearest square foot. Do not include the area of the base. B: 10 ft 8 ft Chapter 12 72 Glencoe Geometry 12 DATE PERIOD Chapter 12 Extended-Response Test SCORE Demonstrate your knowledge by giving a clear, concise solution to each problem. Be sure to include all relevant drawings and justify your answers. You may show your solution in more than one way or investigate beyond the requirements of the problem. 1. Explain the difference between the lateral area and the surface area of a prism. 2. Draw an oblique cylinder and a right cylinder. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 3. Write a practical application problem involving the surface area or lateral area of a solid figure studied in this chapter. 4. Give the dimensions of two cylinders in which the first has a greater volume than the second, but the second has greater surface area than the first. 5. Draw and label the dimensions of a prism and a pyramid that have the same volume. 6. Write a formula for the volume of this solid in terms of the radius r. Explain. 45° r 2r r Chapter 12 73 Glencoe Geometry Assessment NAME NAME DATE PERIOD 12 Standardized Test Practice SCORE (Chapters 1–12) Part 1: Multiple Choice Instructions: Fill in the appropriate circle for the best answer. 1. Which method could you use to prove B E −−− −− F BE AC if AF = BF? (Lesson 4-5) A Show that ABE BAC by SSS, −−− −− C A then BE AC by CPCTC. −−− −− B Show that ABE BAC by ASA, then BE AC by CPCTC. −−− −− C Show that BFE AFC by SAS, then BE AC by CPCTC. −−− −− D Show that ABE BAC by AAS, then BE AC by CPCTC. 1. A B C D 2. F G H J 3. A B C D 4. A square has side length 18 centimeters. Find the area of the square. (Lesson 11-1) F 36 cm2 G 40 cm2 H 81 cm2 J 324 cm2 4. F G H J 5. What can you assume from the figure? (Lesson 10-3) A ABC is isosceles. B ABC is equilateral. C DF = EG D radius of O = x + y 5. A B C D 6. F G H J 7. A B C D 8. F G H J 2. Find a. (Lesson 7-3) F 28.5 G 6.3 9.5 40° H 12.6 J 14 12.6 4.2 40° 3. Find r. (Lesson 8-6) A about 34.0 B about 8.9 a P C about 11.8 D about 6.6 49° r Q 97° 8.9 R E D x O x F A C y G = 210. If K is the 6. Points D, E, and F are on a circle so that mDEF center of the circle, what is m ∠DKF? (Lesson 10-2) F 210 G 105 H 70 J 35 7. Which net could be folded into a triangular prism? (Lesson 12-1) A B C D 8. Find the surface area of a square pyramid with a height of 9 centimeters and base with a side measuring 24 centimeters. (Lesson 12-3) F 1296 cm2 Chapter 12 G 1806 cm2 H 2016 cm2 74 J 8640 cm2 Glencoe Geometry Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. B NAME PERIOD Standardized Test Practice (continued) 9. Find y to the nearest centimeter. (Lesson 8-6) A 19 cm C 34 cm B 28 cm D 37 cm X y Z 9. A 25 cm B C D F G H J C 11. A B C D 3 cm 12. F G H 73° 32 cm Y 10. A plane figure is the locus of all points in a plane equidistant from point B. What is the shape of this figure? (Lesson 10-1) F square G cylinder H rhombus J circle 10. E 11. Find m∠C. (Lesson 10-6) A 18º B 25º C 28º D 60º D 88° 32° B A 12. Find the area of the figure. (Lesson 11-1) F 76 cm2 H 88 cm2 G 80 cm2 J 92 cm2 4 cm 7 cm 2 cm J 4 cm Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 6 cm Part 2: Gridded Response Instructions: Enter your answer by writing each digit of the answer in a column box and then shading in the appropriate circle that corresponds to that entry. 13. Quadrilateral PQSR P is a rectangle. Find a. (Lesson 6-4) R 14. Find x. Assume that segments that appear tangent are tangent. 13. Q (6a - 21)° (2a - 1)° S M 14. 0 0 0 0 1 1 1 1 1 2 2 2 2 2 3 3 3 3 3 4 4 4 4 4 5 5 5 5 5 6 6 6 6 6 7 7 7 7 7 8 8 8 8 8 9 9 9 9 9 0 0 0 0 0 1 1 1 1 1 2 2 2 2 2 3 3 3 3 3 4 4 4 4 4 5 5 5 5 5 6 6 6 6 6 7 7 7 7 7 8 8 8 8 8 9 9 9 9 9 N 5x - 7 (Lesson 10-5) 2x + 8 Chapter 12 0 75 Glencoe Geometry Assessment 12 DATE NAME 12 DATE PERIOD Standardized Test Practice (continued) Part 3: Short Response Instructions: Write your answer in the space provided. to the nearest 15. Find the length of SR tenth. (Lesson 10-2) 15. S 50° T 3m R 16. Find x. (Lesson 10-7) 15 18 17. Find the area of the shaded region to the nearest tenth. (Lesson 11-3) 16. x 30 17. 15 cm 60° 60° 5√3 cm 60° 18. 19. A right circular cone has a slant height of 15 inches and a radius that is 25 inches long. Find the surface area of the cone. Round to the nearest tenth. (Lesson 12-3) 19. 20. A ball has a diameter of 26.5 centimeters. Find the surface area of the ball. Round to the nearest tenth. (Lesson 12-6) 20. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 18. Identify the solid. (Lesson 12-1) 21. Find the following measurements for a sphere with a diameter of 66 meters. Round to the nearest tenth. (Lesson 12-6) 21a. a. surface area b. circumference of the great circle b. c. area of the great circle c. d. surface area of the hemisphere d. Chapter 12 76 Glencoe Geometry Chapter 12 A1 Glencoe Geometry D A D D A 2. The lateral area of a prism is equal to the sum of the areas of each face. 3. The axis of an oblique cylinder is different than the 4. The slant height and height of a regular pyramid are the same. 5. The lateral area of a cone equals the product of π, the radius, and the height of the cone. 6. The volume of a right cylinder with radius r and height h is πr2h. Answers 3 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Chapter Resources PERIOD Representations of Three-Dimensional Figures Study Guide and Intervention DATE E B top view Chapter 12 3. 2. rectangular prism 1 unit high, 5 units long, and 4 units wide left view front view right view 5 4. top view left view front view Lesson 12 -1 4/10/08 9:12:58 PM Glencoe Geometry right view F C right view object front view D A Use isometric dot paper and each orthographic drawing to sketch a solid. 1. cube with 4 units on each side Sketch each solid using isometric dot paper. Exercises Connect the dots on the isometric dot paper to represent the edges of the solid. Shade the tops of each column. Example 2 Use isometric dot paper and the orthographic drawing to sketch a solid. • The top view indicates two columns. top view left view • The right and left views indicate that the height of figure is three blocks. • The front view indicates that the columns have heights 2 and 3 blocks. Example 1 Use isometric dot paper to sketch a triangular prism 3 units high, with two sides of the base that are 3 units long and 4 units long. −− −− Step 1 Draw AB at 3 units and draw AC at 4 units. −−− −−− −− Step 2 Draw AD, BE, and CF, each at 3 units. −−− Step 3 Draw BC and DEF. Draw Isometric Views Isometric dot paper can be used to draw isometric views, or corner views, of a three-dimensional object on two-dimensional paper. 12-1 NAME 6/14/08 2:45:29 001_025_GEOCRMC12_890521.indd PM 5 Glencoe Geometry For those statements that you mark with a D, use a piece of paper to write an example of why you disagree. Chapter 12 Did any of your opinions about the statements change from the first column? • A 10. All spheres and all cubes are similar solids. • D 9. All postulates and properties of Euclidean geometry are true in spherical geometry. After you complete Chapter 12 Step 2 Reread each statement and complete the last column by entering an A or a D. A 8. To find the surface area of a sphere with radius r, multiply πr2 by 4. • D 7. The volume of a pyramid or a cone is found by multiplying the area of the base by the height. height of the cylinder. D STEP 2 A or D 1. The shape of a horizontal cross section of a square pyramid is a triangle. Statement • STEP 1 A, D, or NS Decide whether you Agree (A) or Disagree (D) with the statement. Write A or D in the first column OR if you are not sure whether you agree or disagree, write NS (Not Sure). • PERIOD Read each statement. Before you begin Chapter 12 Extending Surface Area and Volume Anticipating Guide DATE • Step 1 12 NAME 001_025_GEOCRMC12_890521.indd 3 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Answers (Anticipation Guide and Lesson 12-1) PERIOD Representations of Three-Dimensional Figures Study Guide and Intervention (continued) DATE A2 Glencoe Geometry circle 001_025_GEOCRMC12_890521.indd 6 Chapter 12 1. Describe each cross section. Exercises 2. 6 ellipse 3. If the plane cuts across the entire cone, then the resulting cross section will be an ellipse. Angled cross section Vertical cross section Horizontal cross section Glencoe Geometry rectangle If the plane cuts through the cone perpendicular to the base and through the center of the cone, then the resulting cross section will be a triangle. b. c. If the plane is parallel to the base of the cone, then the resulting cross section will be a circle. a. There are several interesting shapes that are cross sections of a cone. Determine the shape resulting from each cross section of the cone. Example solid. The shape of a cross section depends upon the angle of the plane. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. DATE PERIOD Representations of Three-Dimensional Figures Skills Practice 2. rectangular prism 2 units high, 5 units long, and 2 units wide top view left view front view right view Chapter 12 7. 5. triangle square Describe each cross section. 3. 7 8. 6. 4. top view front view rectangle Lesson 12-1 6/14/08 2:45:42 PM Glencoe Geometry right view rectangle left view Use isometric dot paper and each orthographic drawing to sketch a solid. 1. cube 2 units on each edge Use isometric dot paper to sketch each prism. 12-1 NAME 4/10/08001_025_GEOCRMC12_890521.indd 9:13:03 PM 7 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Chapter 12 Cross Sections The intersection of a solid and a plane is called a cross section of the 12-1 NAME Answers (Lesson 12-1) Chapter 12 DATE PERIOD Representations of Three-Dimensional Figures Practice 2. triangular prism 3 units high, whose bases are right triangles with legs 2 units and 4 units long top view left view front view right view 4. top view left view front view A3 circle 6. trapezoid right view Glencoe Geometry Answers 8 Glencoe Geometry a cut through diagonally opposite top and bottom edges to get a rectangle Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. regular hexagon 3. CUBES Nathan marks the midpoints of three edges of a cube as shown. He then slices the cube along a plane that contains these three points. Describe the resulting cross section. Draw the right view of the sculpture. 2. BLOCKS Margot’s three-year-old son made the magnetic block sculpture shown below in corner view. Chapter 12 DATE PERIOD 9 c. Draw the right view. b. Draw the front view. a. Draw the top view. Lesson 12-1 4/10/08 9:13:33 PM Glencoe Geometry 5. DESK SUPPORTS The figure shows the support for a desk. Sample answer: A cylinder with its height equal to its diameter. 4. ENGINEERING Stephanie needs an object whose top view is a circle and whose left and front views are squares. Describe an object that will satisfy these conditions. Representations of Three-Dimensional Figures Word Problem Practice 1. LABELS Jamal removes the label from a cylindrical soup can to earn points for his school. Sketch the shape of the label. 12-1 NAME 4/10/08001_025_GEOCRMC12_890521.indd 9:13:27 PM 9 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 001_025_GEOCRMC12_890521.indd 8 Chapter 12 a cut parallel to the bases to get a square 8. MINERALS Pyrite, also known as fool’s gold, can form crystals that are perfect cubes. Suppose a gemologist wants to cut a cube of pyrite to get a square and a rectanglar face. What cuts should be made to get each of the shapes? Illustrate your answers. All spherical cross sections are circles. 7. SPHERES Consider the sphere in Exercise 5. Based on the cross section resulting from a horizontal and a vertical slice of the sphere, make a conjecture about all spherical cross sections. 5. Sketch the cross section from a vertical slice of each figure. 3. Use isometric dot paper and each orthographic drawing to sketch a solid. 1. rectangular prism 3 units high, 3 units long, and 2 units wide Use isometric dot paper to sketch each prism. 12-1 NAME Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Answers (Lesson 12-1) Enrichment DATE A4 6. 5. Glencoe Geometry 001_025_GEOCRMC12_890521.indd 10 10 4. 3. Chapter 12 2. 1. For each solid shown, draw another solid whose dimensions are twice as large. Isometric dot paper is helpful for drawing solids. Remember to use dashed lines for hidden edges. PERIOD Glencoe Geometry Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Perspective Drawings Graphing Calculator Activity DATE PERIOD H E C B G F Chapter 12 11 Lesson 12-1 6/14/08 2:45:57 PM Glencoe Geometry A'(-7, -4), B'(1, -4), C'(8, -1), D'(0, 3); for sketches, see students’ work. 2. The points A(10, 2, 0), B(10, 10, 0), C(2, 10, 0), and D(3, 3, 4) are vertices of a pyramid. Find the projection coordinates, using a = 25. Round coordinates to the nearest integer. −−− −−− −−− −−− Then graph the pyramid on a graphing calculator by drawing AB, BC, CD, DA, −−− and DB. Make a sketch of the display. A(__, __) B(__, __) C(__, __) D(__, __) A'(-4, 1), B'(1, 1), C'(1, -4), D'(-4, -4), E'(0, 5), F '(5, 5), G'(5, 0) H'(0,0); For sketches, see students’ work. 1. The drawing with the coordinates given below is a cube. A(5, 0, 5), B(5, 5, 5), C(5, 5, 0), D(5, 0, 0), E(0, 0, 5), F(0, 5, 5), G(0, 5, 0), H(0, 0, 0) Use the formulas above to find the projection coordinates of each A point, using a = 45. Round projection coordinates to the nearest integer. Graph the cube on a graphing calculator. Make a sketch of the display. A'(__, __) B'(__, __) C(__, __) D(__, __) E'(__, __) F'(__, __) D G(__, __) H(__, __) The formulas below will draw one type of projection in which the y-axis is drawn horizontally, the z-axis vertically, and the x-axis at an angle of a˚ with the y-axis. If the three-dimensional coordinates of a point are (x, y, z), then the projection coordinates (X, Y) are given by X = x(-cos a) + y and Y = x(-sin a) + z. Although this type of projection gives a fairly good perspective drawing, it does distort some lengths. Today, computers are often used to make perspective drawings, particularly elaborate graphics used in television and movies. The three-dimensional coordinates of objects are figured. Then algebra is used to transform these into two-dimensional coordinates. The graph of these new coordinates is called a projection. The science of perspective drawing studies how to draw a threedimensional object on a two-dimensional page. This science became highly refined during the Renaissance with the work of artists such as Albrecht Dürer and Leonardo da Vinci. 12-1 NAME 4/10/08001_025_GEOCRMC12_890521.indd 9:13:39 PM 11 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Chapter 12 Drawing Solids on Isometric Dot Paper 12-1 NAME Answers (Lesson 12-1) Chapter 12 If a prism has a surface area of S square units, a lateral area of L square units, and each base has an area of B square units, then S = L + 2B or S = Ph + 2B Surface Area of a Prism pentagonal prism Multiply. P = 75, h = 10 Lateral area of a prism ≈ 1524.2 7.5 = 750 + − (75) (2 ) ( tan 36° ) S = L + 2B 1 = 750 + 2 − aP 36° 7.5 a=− tan 36° 7.5 tan 36° = − a 15 cm a A5 10 m 18 in. 12 in. 6. 4. 2. 20 cm 8 cm 12 cm 4m 16 m L = 588 cm2; S = 828 cm2 9 cm 10 cm 10 cm L = 460 in (8 in. × 15 in. base) or 2 8 in. L = 400 in 15 in. (10 in. × 15 in. base) or L = 540 in2 (10 in. × 8 in. base); S = 700 in2 10 in. Glencoe Geometry Answers Glencoe Geometry Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. PERIOD Surface Areas of Prisms and Cylinders If a cylinder has a surface area of S square units, a height of h units, and a base has a radius of r units, then S = L + 2B or 2πrh + 2πr2. Surface Area of a Cylinder radius of base height base 14 cm 6 cm L ≈ 150.8 m2; S ≈ 377.0 m2 4m 12 m L ≈ 113.1 cm2; S ≈ 169.6 cm2 3 cm 3 cm Chapter 12 5. 3. 12 cm L ≈ 301.6 cm2; S ≈ 402.1 cm2 4 cm 13 6. 4. 6 in. 20 cm 1m Lesson 12-2 5/30/09 3:07:00 PM Glencoe Geometry L ≈ 12.6 m2; S ≈ 37.7 m2 2m L ≈ 502.7 cm2; S ≈ 603.2 cm2 8 cm L ≈ 377.0 in2; S ≈ 603.2 in2 10 in. Find the lateral area and surface area of each cylinder. Round to the nearest tenth. 1. 2. Exercises S = 2πrh + 2πr2 Surface area of a cylinder ≈ 527.8 + 2π(6)2 2πrh ≈ 527.8, r = 6 ≈ 754.0 Use a calculator. The lateral area is about 527.8 square centimeters and the surface area is about 754.0 square centimeters. Example Find the lateral and surface area of the cylinder. Round to the nearest tenth. If d = 12 cm, then r = 6 cm. L = 2πrh Lateral area of a cylinder = 2π(6)(14) r = 6, h = 14 12 cm ≈ 527.8 Use a calculator. If a cylinder has a lateral area of L square units, a height of h units, and a base has a radius of r units, then L = 2πrh. Lateral Area of a Cylinder axis base Study Guide and Intervention (continued) DATE Lateral and Surface Areas of Cylinders A cylinder is a solid with bases that are congruent circles lying in parallel planes. The axis of a cylinder is the segment with endpoints at the centers of these circles. For a right cylinder, the axis is also the altitude of the cylinder. 12-2 NAME 001_025_GEOCRMC12_890521.indd 13 6/2/09 4:25:03 PM Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 001_025_GEOCRMC12_890521.indd 12 12 L = 128 in2 (rectangular base) or L = 384 m2; S = 467.1 m2 L = 192 in2 (square base); S = 224 in2 4 in. 4 in. L = 540 in2; S ≈ 663.9 in2 6 in. L = 120 m2; S = 132 m2 4m 3m Chapter 12 5. 3. 1. 2 Find the lateral area and surface area of each prism. Round to the nearest tenth if necessary. Exercises The lateral area is 750 square centimeters and the surface area is about 1524.2 square centimeters. L = Ph = 75(10) = 750 lateral face altitude Example Find the lateral and surface area of the regular pentagonal prism above if each base has a perimeter of 75 centimeters and the height is 10 centimeters. If a prism has a lateral area of L square units, a height of h units, and each base has a perimeter of P units, then L = Ph. Lateral Area of a Prism faces that are not bases are lateral faces. The lateral area is the sum of the area of the lateral faces. The surface area is the sum of the lateral area and the area of the bases. PERIOD lateral edge Surface Areas of Prisms and Cylinders Study Guide and Intervention DATE Lateral and Surface Areas of Prisms In a solid figure, 12-2 NAME Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Answers (Lesson 12-2) Surface Areas of Prisms and Cylinders Skills Practice DATE PERIOD A6 12 yd 10 in. L = 120 in2 S = 168 in2 8 in. 5 in. 6 in. L = 480 yd2 (square base) L = 528 yd2 (rectangular base) S = 768 yd2 10 yd 12 yd 4. 2. 8m 9 cm 12 cm 9 cm L = 324 cm2 S = 394.2 cm2 9 cm 7.8 cm L = 240 m2 (8 × 12 base) L = 288 m2 (12 × 6 base) L = 336 m2 (8 × 6 base) S = 432 m2 12 m 6m 12 in. 10 in. 2 Glencoe Geometry 001_025_GEOCRMC12_890521.indd 14 Chapter 12 L ≈ 37.7 yd S ≈ 94.2 yd2 2 yd L ≈ 377.0 in2 S ≈ 603.2 in2 7. 3 yd 5. 14 8. 6. 8 in. L ≈ 603.2 in S ≈ 1005.3 in2 12 in. 2 2m L ≈ 25.1 m2 S ≈ 50.3 m2 2m Glencoe Geometry Find the lateral area and surface area of each cylinder. Round to the nearest tenth. 3. 1. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Surface Areas of Prisms and Cylinders Practice DATE PERIOD 11 m L = 132 m2; S ≈ 152.8 m2 2m 4. 8 ft 5 yd 9.5 yd 4 yd 5 ft L = 123.5 yd2; S ≈ 139.1 yd2 4 yd L = 224.3 ft2; S = 264.3 ft2 10 ft 7 ft 5 ft 2 L ≈ 1014.7 in ; S ≈ 1581.8 in2 17 in. 19 in. L ≈ 219.9 ft2; S ≈ 377.0 ft2 Chapter 12 7. 5. 15 8. 6. 8.5 m 30 m L ≈ 2261.9 m2; S ≈ 3166.7 m2 12 m L ≈ 106.8 m2; S ≈ 131.9 m2 4m Lesson 12-2 3/5/13 10:08:32 PM Glencoe Geometry Find the lateral area and surface area of each cylinder. Round to the nearest tenth. 3. 32 cm L = 1920 cm2 (square base) or L = 1410 cm2 (rectangular base); S = 2370 cm2 15 cm 15 cm Find the lateral and surface area of each prism. Round to the nearest tenth if necessary. 2. 1. 12-2 NAME 5/30/09001_025_GEOCRMC12_890521.indd 3:07:04 PM 15 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Chapter 12 Find the lateral area and surface area of each prism. Round to the nearest tenth if necessary. 12-2 NAME Answers (Lesson 12-2) Chapter 12 A7 15" 15 ft 20 ft 16 ft What is the lateral surface area of the stairwell? 9 ft 2. STAIRWELLS Management decides to enclose stairs connecting the first and second floors of a parking garage in a stairwell shaped like an oblique rectangular prism. 5850 in2 What is the lateral surface area of this “Z”? Glencoe Geometry 14,250.26 in2 30,536.28 in2 Glencoe Geometry b. Another tower is constructed by placing the original tower on top of another cylinder with a height of 18 inches and a radius of 54 inches. What is the total surface area of the new tower? Round your answer to the nearest hundredth. Answers 16 18 in. a. What is the total surface area of the tower? Round your answer to the nearest hundredth. 18 in. 5. TOWERS A circular tower is made by placing one cylinder on top of another. Both cylinders have a height of 18 inches. The top cylinder has a radius of 18 inches and the bottom cylinder has a radius of 36 inches. 628.32 in2 4. EXHAUST PIPES An exhaust pipe is shaped like a cylinder with a height of 50 inches and a radius of 2 inches. What is the lateral surface area of the exhaust pipe? Round your answer to the nearest hundredth. PERIOD Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Enrichment DATE PERIOD πr 40 h=− 2 r h Chapter 12 1 cent 1 cent 4 cents 6 cents 1 cent 3 cents 1 cent 1 cent 2 cents 5 cents Cost Cylinder Cost Top & Bottom 17 12.24 10.84 9.34 7.71 5.88 h Minimum Lesson 12-2 6/2/09 4:28:37 PM Glencoe Geometry The height increases as the cost of the top and bottom go up. 6. Compute the table for the cost value given. What happens to the height of the can as the cost of the top and bottom increases? See students’ work. Sample answer: The manufacturer might make the cans taller and narrower. 5. What would you expect to happen as the cost of the top and bottom increases? 80 80 2 cents: C = 4πr2 + − = 5.88 in. ; 4 cents: C = 8πr2 + − = 9.34 in. r r 4. Repeat the procedure using 2 cents per square inch for the top and bottom and 4 cents per square inch for the top and bottom. The minimum height is 7.71 inches, which gives a minimum cost of 93. 3. Use a graphing calculator to graph the formula, letting Y1 represent the cost and X represent r. Use the graph to estimate the point at which the cost is minimized. πr 40 80 C = 3(2πr2) + 1(2πr − ) or 6πr2 + − 2 r 2. Write a formula for the cost in terms of r. 1. Write the value of h in terms of r, given v = πr 2 h . Suppose that a manufacturer wants to make a can that has a volume of 40 cubic inches. The cost to make the can is 3 cents per square inch for the top and bottom and 1 cent per square inch for the side. Minimizing Cost in Manufacturing 12-2 NAME 001_025_GEOCRMC12_890521.indd 17 4/10/08 9:14:07 PM Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 001_025_GEOCRMC12_890521.indd 16 Chapter 12 396 in2 3. CAKES A cake is a rectangular prism with height 4 inches and base 12 inches by 15 inches. Wallace wants to apply frosting to the sides and the top of the cake. What is the surface area of the part of the cake that will have frosting? 840 ft2 DATE Surface Areas of Prisms and Cylinders Word Problem Practice 1. LOGOS The Z company specializes in caring for zebras. They want to make a 3-dimensional “Z” to put in front of their company headquarters. The “Z” is 15 inches thick and the perimeter of the base is 390 inches. 12-2 NAME Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Answers (Lesson 12-2) Surface Areas of Pyramids and Cones Study Guide and Intervention DATE where ℓ is the slant height, P is the perimeter of the base, and B is the area of the base. 1 The surface area S of a regular pyramid is S = − Pℓ + B, 2 is the slant height and P is the perimeter of the base. lateral edge height base A8 Simplify. P = 4 12 or 48, ℓ = 10 Lateral area of a regular pyramid = 384 = 240 + 144 1 S=− Pℓ + B 2 2 1 − Pℓ = 240, B = 12 · 12 or 144 Surface area of a regular pyramid 15 cm Glencoe Geometry 001_025_GEOCRMC12_890521.indd 18 Chapter 12 L ≈ 266.7 cm2; S ≈ 400.0 cm2 60° L ≈ 450 cm2; S ≈ 547.4 cm2 20 cm 3. 10 cm 1. 18 4. 2. 45° 15 in. Glencoe Geometry L ≈ 326.3 in2; S ≈ 456.8 in2 8.7 in. 6 in. L ≈ 362.0 ft2; S ≈ 618.0 ft2 8 ft Find the lateral area and surface area of each regular pyramid. Round to the nearest tenth if necessary. Exercises The lateral area is 240 square centimeters, and the surface area is 384 square centimeters. = 240 1 L=− Pℓ 2 1 = − (48)(10) 2 Find the slant height. ℓ2 = 62 + 82 Pythagorean Theorem ℓ2 = 100 Simplify. ℓ = 10 Take the positive square root of each side. Example For the regular square pyramid above, find the lateral area and surface area if the length of a side of the base is 12 centimeters and the height is 8 centimeters. Round to the nearest tenth if necessary. Surface Area of a Regular Pyramid Lateral Area of a Regular Pyramid 1 The lateral area L of a regular pyramid is L = − Pℓ, where ℓ 2 A pyramid is a solid with a polygon base. The lateral faces intersect in a common slant height point known as the vertex. The altitude is the segment from the vertex that is perpendicular to the base. For a regular pyramid, the base is a regular polygon and the altitude has an endpoint at the center of the base. All the lateral edges are congruent and all the lateral faces are congruent isosceles triangles. The height of each lateral face is called the slant height. PERIOD Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. PERIOD V base slant height axis right cone altitude Simplify. r = 6, ℓ = 10 Lateral area of a right cone S = πrℓ + πr2 ≈ 188.5 + π(62) ≈ 301.6 Simplify. πrℓ ≈ 188.5, r = 6 Surface area of a right cone 9 cm 12 cm 2 L ≈ 204.2 cm ; S ≈ 282.7 cm2 13 cm 12 cm L ≈ 424.1 cm2; S ≈ 678.6 cm2 Chapter 12 3. 1. 19 4. 2. L ≈ 71.1 in2; S ≈ 121.4 in2 4 in. 45° L ≈ 157.1 ft2; S ≈ 235.6 ft2 30° 5 ft Lesson 12-3 3/27/10 10:45:38 PM Glencoe Geometry Find the lateral area and surface area of each cone. Round to the nearest tenth if necessary. Exercises The lateral area is about 188.5 square centimeters and the surface area is about 301.6 square centimeters. L = πrℓ = π(6)(10) ≈ 188.5 Find the slant height. ℓ2 = 6 2 + 8 2 Pythagorean Theorem ℓ2 = 100 Simplify. ℓ = 10 Take the positive square root of each side. Example For the right cone above, find the lateral area and surface area if the radius is 6 centimeters and the height is 8 centimeters. Round to the nearest tenth if necessary. The surface area S of a right cone is S = πr + πr2, where r is the radius and is the slant height. Surface Area of a Cone oblique cone The lateral area L of a right circular cone is L = πr, where r is the radius and is the slant height. base Lateral Area of a Cone a circular base and a vertex. The axis of the cone is the segment with endpoints at the vertex and the center of the base. If the axis is also the altitude, then the cone is a right cone. If the axis is not the altitude, then the cone is an oblique cone. V Surface Areas of Pyramids and Cones Study Guide and Intervention (continued) DATE Lateral and Surface Areas of Cones A cone has 12-3 NAME 3/27/10 001_025_GEOCRMC12_890521.indd 10:44:01 PM 19 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Chapter 12 Lateral and Surface Areas of Pyramids 12-3 NAME Answers (Lesson 12-3) Chapter 12 Surface Areas of Pyramids and Cones Skills Practice DATE PERIOD 4 cm L ≈ 283.2 m2 S ≈ 455.3 m2 10 m 9m L = 56 cm2 S = 72 cm2 7 cm 4. 2. L ≈ 389.0 ft2 S ≈ 585.0 ft2 12 ft L = 480 in2 S = 646.3 in2 8 in. 20 in. 14 ft A9 5m L ≈ 527.8 in2 S ≈ 728.8 in2 8 in. 21 in. L ≈ 219.9 m2 S ≈ 298.5 m2 14 m Glencoe Geometry 25 ft L ≈ 480.7 mm2 S ≈ 735.1 mm2 17 mm 9 mm L ≈ 845.9 ft2 S ≈ 1160.1 ft2 10 ft Answers 20 8. 6. Glencoe Geometry Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Surface Areas of Pyramids and Cones Practice DATE PERIOD 9 yd L = 162.5 ft2; S ≈ 205.5 ft2 5 ft 13 ft L = 180 yd2; S = 261 yd2 10 yd 4. 2. 7m 2.5 cm L ≈ 60 cm2; S ≈ 76.2 cm2 8 cm L = 126 m2; S ≈ 147.2 m2 12 m L ≈ 80.5 m2; S ≈ 130.7 cm2 5m 4m 6. 21 cm 468.8 cm2 ; S ≈ 640.7 cm2 7 cm Chapter 12 about 2513.3 cm2 21 Lesson 12-3 5/30/09 3:07:34 PM Glencoe Geometry 10. HATS Cuong bought a conical hat on a recent trip to central Vietnam. The basic frame of the hat is 16 hoops of bamboo that gradually diminish in size. The hat is covered in palm leaves. If the hat has a diameter of 50 centimeters and a slant height of 32 centimeters, what is the lateral area of the conical hat? 3.8 m2 9. GAZEBOS The roof of a gazebo is a regular octagonal pyramid. If the base of the pyramid has sides of 0.5 meter and the slant height of the roof is 1.9 meters, find the area of the roof. 1338.6 in2 8. Find the surface area of a cone if the height is 12 inches and the diameter is 27 inches. 669.3 cm2 7. Find the surface area of a cone if the height is 14 centimeters and the slant height is 16.4 centimeters. 5. Find the lateral area and surface area of each cone. Round to the nearest tenth if necessary. 3. 1. Find the lateral area and surface area of each regular pyramid. Round to the nearest tenth if necessary. 12-3 NAME 6/14/08001_025_GEOCRMC12_890521.indd 2:46:29 PM 21 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 001_025_GEOCRMC12_890521.indd 20 Chapter 12 7. 5. Find the lateral area and surface area of each cone. Round to the nearest tenth. 3. 1. Find the lateral area and surface area of each regular pyramid. Round to the nearest tenth if necessary. 12-3 NAME Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Answers (Lesson 12-3) A10 Glencoe Geometry 001_025_GEOCRMC12_890521.indd 22 Chapter 12 6.54 in2 What is the lateral surface area of this pyramid? Round your answers to the nearest hundredth. 3. PAPERWEIGHTS Daphne uses a paperweight shaped like a pyramid with a regular hexagon for a base. The side length of the regular hexagon is 1 inch. The altitude of the pyramid is 2 inches. 68 in2 2. TETRAHEDRON Sung Li builds a paper model of a regular tetrahedron, a pyramid with an equilateral triangle for the base and three equilateral triangles for the lateral faces. One of the faces of the tetrahedron has an area of 17 square inches. What is the total surface area of the tetrahedron? 600 cm2 22 PERIOD 3814.89 in2 Glencoe Geometry c. What is the lateral surface area of the megaphone? 158.95 in2 b. What is the lateral surface area of the tip that is removed? 3973.84 in2 a. What is the lateral surface area of the original cone? 5. MEGAPHONES A megaphone is formed by taking a cone with a radius of 20 centimeters and an altitude of 60 centimeters and cutting off the tip. The cut is made along a plane that is perpendicular to the axis of the cone and intersects the axis 12 centimeters from the vertex. Round your answers to the nearest hundredth. 78.54 in2 4. SPRAY PAINT A can of spray paint shoots out paint in a cone shaped mist. The lateral surface area of the cone is 65π square inches when the can is held 12 inches from a canvas. What is the area of the part of the canvas that gets sprayed with paint? Round your answer to the nearest hundredth. Surface Areas of Pyramids and Cones Word Problem Practice DATE Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Enrichment DATE PERIOD 120° height of cone = 4.5 cm (to nearest tenth of a centimeter) lateral area = 24π cm 2 diameter of base = 8 cm 6 cm Chapter 12 12. 23 13. Lesson 12-3 5/30/09 4:13:23 PM Glencoe Geometry height of cone = 8.7 cm (to nearest tenth of a centimeter) lateral area = 50π cm2 diameter of base = 10 cm 20 cm Make a paper pattern for each cone with the given measurements. Then cut the pattern out and make the cone. Find the measurements. 11. Find the total surface area. 5.25 cm2 10. Find the lateral area. 3π cm2 9. Use the Pythagorean Theorem to calculate the height of the cone. Use a decimal approximation. Check your calculation by measuring the height with a metric ruler. 1.32 cm 8. What is the slant height of the cone? 2 cm 7. What is the circumference of the base of the cone? 3π cm 6. Measure the diameter of the circular base of the cone. 3 cm 5. Cut out the pattern and tape it together to form a cone. See students’ work. 4. How long is the circular arc that is the outside of the pattern? 3π cm 3. What is the circumference of the complete circle? 4π cm 4 2. The pattern is what fraction of the 3 complete circle? − 1. Measure the radius of the circle to the nearest centimeter. 2 cm The pattern at the right is made from a circle. It can be folded to make a cone. Cone Patterns 12-3 NAME 4/10/08001_025_GEOCRMC12_890521.indd 9:14:35 PM 23 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Chapter 12 1. PAPER MODELS Patrick is making a paper model of a castle. Part of the model involves 20 cm 20 cm 15 cm cutting out the net shown and folding it into a pyramid. The pyramid has a square base. What is the lateral surface area of the resulting pyramid? 12-3 NAME Answers (Lesson 12-3) Chapter 12 Surface Areas of Cones Spreadsheet Activity DATE PERIOD A11 8. r = 1.5 mm, = 4.5 mm 28.3 mm2 7. r = 10 mm, = 20 mm 942.5 mm2 Glencoe Geometry Answers Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Volumes of Prisms and Cylinders Study Guide and Intervention DATE 3 cm 8 ft 4 cm 2 cm 27 cm3 1.5 cm 30° 8 ft 467.7 ft3 15 ft 12 ft 512 ft3 8 ft Chapter 12 5. 3. 1. 6 cm Find the volume of each prism. Exercises V = Bh Volume of a prism = (7)(3)(4) B = (7)(3), h = 4 = 84 Multiply. The volume of the prism is 84 cubic centimeters. 7 cm Find the volume 3.5 ft base 6. 4. 15 ft 84 yd3 7 yd 1800 ft3 10 ft 9 cm3 3 cm 1.5 cm 4 yd 12 ft 4 cm 3 yd Lesson 12-4 4/10/08 9:14:47 PM Glencoe Geometry V = Bh Volume of a prism = (6.3)(3.5) B = 6.3, h = 3.5 = 22.05 Multiply. The volume is 22.05 cubic feet. 2. 25 cubic foot cubic yard 27 cubic feet = 1 cubic yard PERIOD Example 2 Find the volume of the prism if the area of each base is 6.3 square feet. If a prism has a volume of V cubic units, a height of h units, and each base has an area of B square units, then V = Bh. 4 cm Example 1 of the prism. Volume of a Prism Volumes of Prisms The measure of the amount of space that a three-dimensional figure encloses is the volume of the figure. Volume is measured in units such as cubic feet, cubic yards, or cubic meters. One cubic unit is the volume of a cube that measures one unit on each edge. 12-4 NAME 5/30/09001_025_GEOCRMC12_890521.indd 3:07:47 PM 25 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 001_025_GEOCRMC12_890521.indd 24 24 Chapter 12 Glencoe Geometry 12. r = 11 m, = 13 m 829.4 m2 11. r = 10 m, = 2 m 377.0 m2 10. r = 10 cm, = 15 cm 785.4 cm2 6. r = 3 ft, = 1.5 ft 42.4 ft2 5. r = 1 ft, = 3 ft 12.6 ft2 9. r = 6.2 cm, = 1.2 cm 144.1 cm 4. r = 5 in., = 11 in. 251.3 in2 3. r = 3 in., = 7 in. 94.2 in2 2 2. r = 6 m, = 2 m 150.8 m2 1. r = 12 m, = 2.3 m 539.1 m2 Use a spreadsheet to find the surface area of each cone with the given dimensions. Round to the nearest tenth. Exercises The surface area of the cone is 60.5 cm2 to the nearest tenth. Click on the bottom right corner of cell C1 and drag it to C2. This returns the surface area of the cone. C Step 2 Sheet 1 B Use cell A2 for the radius of the cone and cell B2 for the slant height. 1 2 Step 1 Example 2 Use a spreadsheet to determine the surface area of a cone that has a radius of 2.5 centimeters and a slant height of 5.2 centimeters. Round to the nearest tenth. A In cell C1, enter an equals sign followed by PI()*A1*B1 + PI()*A1^2. Then press ENTER. This will return the surface area of the cone. Step 2 The surface area of the conical box is 84.8 in2 to the nearest tenth. Use cell A1 for the radius of the cone and cell B1 for the height. Step 1 Example 1 Lucy wants to wrap a Mother’s Day gift. The gift she has bought for her mother is in a conical box that has a slant height of 6 inches and has a radius of 3 inches. She must determine the surface area of the box to determine how much wrapping paper to buy. Use a spreadsheet to determine the surface area of the box. Round to the nearest tenth. You can use a spreadsheet to determine the surface area of a cone. 12-3 NAME Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Answers (Lesson 12-3 and Lesson 12-4) PERIOD Volumes of Prisms and Cylinders Study Guide and Intervention (continued) DATE A12 5 in. 8 in. 10 cm 12 ft 2 ft 652.4 cm3 13 cm 84.8 ft3 1.5 ft 12.6 ft3 Glencoe Geometry 026_044_GEOCRMC12_890521.indd 26 Chapter 12 5. 3. 1. 1 ft h 26 6. 4. 18 cm 4 yd 12.6 yd3 1 yd 6283.2 ft3 20 ft 20 ft 226.2 cm3 2. 2 cm Glencoe Geometry V = πr2h Volume of a cylinder = π(4)2(12) r = 4, h = 12 ≈ 603.2 Simplify. The Volume is about 603.2 cubic inches. Use the Pythagorean Theorem to find the height of the cylinder. h2 + 52 = 132 Pythagorean Theorem h2 = 144 Simplify. h = 12 Take the square root of each side. h 13 in. Find the volume of each cylinder. Round to the nearest tenth. Exercises V = πr h Volume of a cylinder = π(3)2(4) r = 3, h = 4 ≈ 113.1 Simplify. The volume is about 113.1 cubic centimeters. 2 4 cm 3 cm Find the volume of the oblique cylinder. Example 2 If a cylinder has a volume of V cubic units, a height of h units, and the bases have a radius of r units, then V = πr 2h. Find the volume of the cylinder. Example 1 Volume of a Cylinder height and the area of the base. When a solid is not a right solid, use Cavalieri’s Priniciple to find the volume. The principle states that if two solids have the same height and the same cross sectional area at every level, then they have the same volume. r Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Volumes of Prisms and Cylinders Skills Practice DATE PERIOD 16 cm 15 mm 16,257.7 mm3 23 mm 90 m3 3m 13 m 2304 cm3 18 cm 8 cm 5m 6. 4. 2. 226.2 yd3 10 yd 6 yd 5280 in3 16 in. 96 ft3 6 ft 34 in. 22 in. 8 ft 2 ft 1224 cm3 17 cm Chapter 12 7. 18 cm 4 cm 27 8. 141.4 in3 3 in. 5 in. Lesson 12-4 6/14/08 2:47:17 PM Glencoe Geometry Find the volume of each oblique prism or cylinder. Round to the nearest tenth if necessary. 5. 3. 1. Find the volume of each prism or cylinder. Round to the nearest tenth if necessary. 12-4 NAME 4/14/08026_044_GEOCRMC12_890521.indd 9:21:18 PM 27 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Chapter 12 Volumes of Cylinders The volume of a cylinder is the product of the 12-4 NAME Answers (Lesson 12-4) Chapter 12 Volumes of Prisms and Cylinders Practice DATE PERIOD A13 17.5 mm 2600 yd3 13 yd 20 yd 3518.6 mm3 16 mm 2040 m3 17 m 26 m 10 yd 10 m 2 6. 4. 2. 5 in. 8 cm 25 ft 5 in. 9 in. 6031.9 cm3 30 cm 923.6 ft3 7 ft 97.4 in3 5 in. Glencoe Geometry Answers 28 Glencoe Geometry Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 6 ft 6 ft Chapter 12 3840 cm3 3. FRAMES Margaret makes a square frame out of four pieces of wood. Each piece of wood is a rectangular prism with a length of 40 centimeters, a height of 4 centimeters, and a depth of 6 centimeters. What is the total volume of the wood used in the frame? 57.6 ft3 What is the volume of the seat? 3 1 5 ft 2. BENCH Inside a lobby, there is a piece of furniture for sitting. The furniture is shaped like a simple block with a square base 6 feet on each side and a height of 3 1− feet. 12 in. 29 PERIOD 883,573 ft3 Lesson 12-4 4/10/08 9:11:41 PM Glencoe Geometry b. If instead of a rectangular shape, the tunnel had a semicircular shape with a 50-foot diameter, what would be its volume? Round your answer to the nearest cubic foot. 900,000 ft3 a. What will the volume of the tunnel be? 5. TUNNELS Construction workers are digging a tunnel through a mountain. The space inside the tunnel is going to be shaped like a rectangular prism. The mouth of the tunnel will be a rectangle 20 feet high and 50 feet wide and the length of the tunnel will be 900 feet. 8 - π cm3 What is the exact volume of the pencil grip? 4. PENCIL GRIPS A pencil grip is shaped like a triangular prism with a cylinder removed from the middle. The base of the prism is a right isosceles triangle with leg lengths of 2 centimeters. The diameter of the base of the removed cylinder is 1 centimeter. The heights of the prism and the cylinder are the same, and equal to 4 centimeters. Volumes of Prisms and Cylinders 2035.8 in3 5 DATE Word Problem Practice 1. TRASH CANS The Meyer family uses a kitchen trash can shaped like a cylinder. It has a height of 18 inches and a base diameter of 12 inches. What is the volume 18 in. of the trash can? Round your answer to the nearest tenth of a cubic inch. 12-4 NAME 4/14/08 026_044_GEOCRMC12_890521.indd 11:10:42 AM 29 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 026_044_GEOCRMC12_890521.indd 28 Chapter 12 1275 lb c. If a cubic foot of water weighs about 62.4 pounds, what is the weight of the water in the aquarium to the nearest five pounds? 152.9 gal b. If there are 7.48 gallons in a cubic foot, how many gallons of water does the aquarium hold? 20.4 ft3 a. What is the volume of the aquarium in cubic feet? 7. AQUARIUM Mr. Gutierrez purchased a cylindrical aquarium for his office. 1 The aquarium has a height of 25 − inches and a radius of 21 inches. 5. 3. 1. Find the volume of each prism or cylinder. Round to the nearest tenth if necessary. 12-4 NAME Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Answers (Lesson 12-4) Enrichment PERIOD A14 2 Glencoe Geometry 026_044_GEOCRMC12_890521.indd 30 Chapter 12 visible surface area = 164 in volume = 136 in3 30 visible surface area = 19 in2 visible surface area = 17 in2 5 in. volume = 5 in3 volume = 5 in3 3 in. 3 in. Glencoe Geometry 4 in. 5 in. 3 in. visible surface area = 19 in2 volume = 5 in3 8 in. 3 in. 4 in. 5. visible surface area = 15 in2 visible surface area = 14 in2 4. volume = 4 in3 2. volume = 4 in3 6. Find the volume and the visible surface area of the figure at the right. 3. 1. Use paper, scissors, and tape to make five cubes that have one-inch edges. Arrange the cubes to form each shape shown. Then find the volume and the visible surface area. In other words, do not include the area of surface covered by other cubes or by the table or desk. DATE Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Volumes of Pyramids and Cones Study Guide and Intervention DATE 8 ft 10 ft 1200 in3 15 in. 110.9 cm3 8 cm 12 cm 320 ft3 12 ft 10 ft Chapter 12 5. 3. 1. 15 in. 16 in. 4 cm 8 ft 31 6. 4. 2. 10 ft 64 yd3 5 yd 561.2 ft3 regular hexagon 120 ft3 15 ft 6 yd 6 ft 8 yd 6 ft 18 ft Lesson 12-5 4/10/08 9:11:47 PM Glencoe Geometry Find the volume of each pyramid. Round to the nearest tenth if necessary. Exercises ≈ 213.3 Multiply. The volume is about 213.3 cubic feet. B = (8)(8), h = 10 Volume of a pyramid Find the volume of the square pyramid. 3 1 =− (8)(8)10 3 1 Bh V=− Example 3 If a pyramid has a volume of V cubic units, a height of h units, 1 and a base with an area of B square units, then V = − Bh. Volume of a Pyramid 8 ft PERIOD that have the same base and the same height. It is clear that the volume of the pyramid is less than the volume of the prism. More specifically, the volume of the pyramid is one-third of the volume of the prism. Volumes of Pyramids This figure shows a prism and a pyramid 12-5 NAME 4/11/08026_044_GEOCRMC12_890521.indd 6:34:37 AM 31 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Chapter 12 Visible Surface Area 12-4 NAME Answers (Lesson 12-4 and Lesson 12-5) Chapter 12 PERIOD Volumes of Pyramids and Cones Study Guide and Intervention (continued) DATE r = 5, h = 12 Volume of a cone Find the volume of the cone. A15 3 2513.3 ft3 26 ft 1131.0 in3 12 in. Glencoe Geometry 379.1 cm3 16 cm 45° 1332.9 yd3 20 yd 18 yd 45° 3 10 ft 670.2 ft Answers 32 6. 4. 2. 8 ft 5 cm 12 cm r Glencoe Geometry h Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Volumes of Pyramids and Cones Skills Practice DATE PERIOD 10 in. 1231.5 yd3 14 yd 357.8 in3 14 in. 25 yd 8 in. 5 ft 25 m 12 m 6. 1210.6 mm3 18 mm 3769.9 m3 4. 7 cm 74.7 cm3 8 cm 66° 4 cm 31 ft3 4 ft Chapter 12 7. 4 ft 6 ft 33 8. 452.4 cm3 12 cm 6 cm Lesson 12-5 6/14/08 2:47:35 PM Glencoe Geometry Find the volume of each oblique pyramid or cone. Round to the nearest tenth if necessary. 5. 3. 66.7 ft3 5 ft 8 ft Find the volume of each pyramid or cone. Round to the nearest tenth if necessary. 1. 2. 12-5 NAME 4/10/08026_044_GEOCRMC12_890521.indd 9:11:52 PM 33 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 026_044_GEOCRMC12_890521.indd 32 20 ft 30 in. 10 cm 6 cm 301.6 cm Chapter 12 5. 3. 1. Find the volume of each cone. Round to the nearest tenth. Exercises 3 If a cone has a volume of V cubic units, a height of h units, 1 2 and the bases have a radius of r units, then V = − πr h. ≈ 314.2 Simplify. The volume of the cone is about 314.2 cubic centimeters. 3 1 =− π(5)212 3 1 2 πr h V=− Example Volume of a Cone Volumes of Cones For a cone, the volume is one-third the product of the height and the area of the base. The base of a cone is a circle, so the area of the base is πr2. 12-5 NAME Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Answers (Lesson 12-5) Volumes of Pyramids and Cones Practice PERIOD A16 3 132 in 6 in. 3 9.2 yd 11 in. 9 ft 6 in. 1419.4 ft3 19 ft 317.5 yd 9.2 yd 13 yd 6. 4. 2. 3 3 4688.3 ft 11 ft 1104.6 mm3 12 mm 2395.8 cm 25 cm 37 ft 52° 12.5 cm 23 cm Glencoe Geometry 026_044_GEOCRMC12_890521.indd 34 Chapter 12 about 341,413.3 m3 34 Glencoe Geometry 8. HISTORY The start of the pyramid age began with King Zoser’s pyramid, erected in the 27th century B.C. In its original state, it stood 62 meters high with a rectangular base that measured 140 meters by 118 meters. Find the volume of the original pyramid. about 15.9 m3 7. CONSTRUCTION Mr. Ganty built a conical storage shed. The base of the shed is 4 meters in diameter and the height of the shed is 3.8 meters. What is the volume of the shed? 5. 3. 1. Find the volume of each pyramid or cone. Round to the nearest tenth if necessary. 12-5 DATE Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Chapter 12 60.63 ft3 What was the volume of the teepee? Round your answer to the nearest hundredth. 65˚ 3. TEEPEE Caitlyn made a teepee for a class project. Her teepee had a diameter of 6 feet. The angle the side of the teepee made with the ground was 65°. 5400 yd3 What is the volume of the greenhouse? 30 yd 2. GREENHOUSES A greenhouse has the shape of a square pyramid. The base has a side length of 30 yards. The height of the greenhouse is 18 yards. 35 PERIOD 3 feet 592 ft3 Lesson 12-5 5/30/09 3:08:51 PM Glencoe Geometry c. What is the volume of the stage? 432 ft3 b. What is the volume of the top of the pyramid that is removed to get the stage? 1024 ft3 a. What is the volume of the entire square pyramid that the stage is part of? 16 feet 12 feet 5. STAGES A stage has the form of a square pyramid with the top sliced off along a plane parallel to the base. The side length of the top square is 12 feet and the side length of the bottom square is 16 feet. The height of the stage is 3 feet. 6.28 ft3 What is the volume of the stone that the sculptor must remove? Round your answer to the nearest hundredth. 4. SCULPTING A sculptor wants to remove stone from a cylindrical block 3 feet high and turn it into a cone. The diameter of the base of the cone and cylinder is 2 feet. Volumes of Pyramids and Cones What is the volume of the cone? Round your answer to the nearest hundredth. 5.03 in3 DATE Word Problem Practice 1. ICE CREAM DISHES The part of a dish designed for ice cream is shaped like an upside-down cone. The base of the cone has a radius of 2 inches and the height is 1.2 inches. 12-5 NAME 4/10/08026_044_GEOCRMC12_890521.indd 9:12:00 PM 35 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Chapter 12 18 yd NAME Answers (Lesson 12-5) Chapter 12 Enrichment DATE ) A17 19.5 cm 5 cm 6 cm 13 cm 9 cm 6m 12 m 8m trapezoids; 151.6 m3 5m 3m 2.25 m 4.5 m rectangles; 617.5 cm3 Glencoe Geometry 4.5 in. 7.5 in. 3 in. 13 ft circles; 3480.9 ft3 12 ft circles; 335.8 in3 Answers 36 4. 2. Glencoe Geometry 7 ft PERIOD Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Surface Areas and Volumes of Spheres Study Guide and Intervention DATE PERIOD If a sphere has a surface area of S square units and a radius of r units, then S = 4πr2. Simplify. r=6 Surface area of a sphere 6 cm r 3 ft 5m 84.8 ft2 314.2 m2 4. 2. Chapter 12 37 6. hemisphere: area of great circle ≈ 4π ft2 37.7 ft2 7 in 9 cm 5. sphere: circumference of great circle = π cm 3.1 cm2 3. 1. Lesson 12-6 5/30/09 3:09:01 PM Glencoe Geometry 190.9 cm2 153.9 in2 Find the surface area of each sphere or hemisphere. Round to the nearest tenth. Exercises The surface area is 452.4 square centimeters. S = 4πr2 = 4π(6)2 ≈ 452.4 Example Find the surface area of a sphere to the nearest tenth if the radius of the sphere is 6 centimeters. Surface Area of a Sphere as the total area of all of the nonoverlapping strips it would take to cover the sphere. If r is the radius of the sphere, then the area of a great circle of the sphere is πr2. The total surface area of the sphere is four times the area of a great circle. Surface Areas of Spheres You can think of the surface area of a sphere 12-6 NAME 6/1/09 026_044_GEOCRMC12_890521.indd 10:19:21 AM 37 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 026_044_GEOCRMC12_890521.indd 36 Chapter 12 3. 1. Describe the shape of the bases of each frustum. Then find the volume. Round to the nearest tenth. where h = height (perpendicular distance between the bases), B1 = area of top base, and B2 = area of bottom base. ( 1 V=− h B1 + B2 + √ B1B2 , 3 A frustum is a figure formed when a plane intersects a pyramid or cone so that the plane is parallel to the solid’s base. The frustum is the part of the solid between the plane and the base. To find the volume of a frustum, the areas of both bases must be calculated and used in the formula. Frustums 12-5 NAME Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Answers (Lesson 12-5 and Lesson 12-6) PERIOD Surface Areas and Volumes of Spheres A18 523.6 ft3 5 ft 2. 6 in. 452.4 in3 Glencoe Geometry 026_044_GEOCRMC12_890521.indd 38 Chapter 12 38 6. hemisphere: area of great circle ≈ 50 m2 133.0 m3 5. sphere: circumference of great circle ≈ 25 ft 263.9 ft3 4. hemisphere: radius 5 in. 261.8 in3 1. 3. 8 cm r Glencoe Geometry 8578.6 in3 16 in. Find the volume of each sphere or hemisphere. Round to the nearest tenth. Exercises ≈ 2144.7 Simplify. The volume is about 2144.7 cubic centimeters. r=8 Volume of a sphere Find the volume of a sphere with radius 8 centimeters. Example 4 3 πr V=− 3 4 =− π (8)3 3 4 3 If a sphere has a volume of V cubic units and a radius of r units, then V = − πr . Volume of a Sphere length of its radius. If you know the length of the radius of a sphere, you can calculate its volume. 3 Study Guide and Intervention (continued) DATE Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. PERIOD Surface Areas and Volumes of Spheres Skills Practice DATE 615.8 in2 7 in. 2. 3217.0 m2 32 m 2226.1 cm3 16.2 cm 6. 94.8 ft 446,091.2 ft3 Chapter 12 9. sphere: diameter = 10 in. 523.6 in3 39 8. sphere: circumference of a great circle ≈ 26 m 296.8 m3 7. hemisphere: diameter = 48 yd 28,952.9 yd3 5. Lesson 12-6 5/30/09 3:09:16 PM Glencoe Geometry Find the volume of each sphere or hemisphere. Round to the nearest tenth. 4. sphere: area of great circle ≈ 28.6 in2 114.4 in2 3. hemisphere: radius of great circle = 8 yd 603.2 yd2 1. Find the surface area of each sphere or hemisphere. Round to the nearest tenth. 12-6 NAME 3/27/10 026_044_GEOCRMC12_890521.indd 10:47:18 PM 39 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Chapter 12 Volumes of Spheres A sphere has one basic measurement, the 12-6 NAME Answers (Lesson 12-6) Chapter 12 PERIOD Surface Areas and Volumes of Spheres Practice DATE 530.9 cm2 6.5 cm 2. A19 7832.9 ft3 12.32 ft 6. Glencoe Geometry Answers 40 Glencoe Geometry Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. PERIOD 83,322,891.2 km2 3. MOONS OF SATURN The planet Saturn has several moons. These can be modeled accurately by spheres. Saturn’s largest moon Titan has a radius of about 2575 kilometers. What is the approximate surface area of Titan? Round your answer to the nearest tenth. 95.426 in3 2. BILLIARDS A billiard ball set consists 1 of 16 spheres, each 2 − inches in 4 diameter. What is the total volume of a complete set of billiard balls? Round your answer to the nearest thousandth of a cubic inch. 41 1.91 Lesson 12-6 5/30/09 3:09:26 PM Glencoe Geometry c. What is the ratio of the surface area of the cube to the surface area of the sphere? Round your answer to the nearest hundredth. 12.57 in2 b. What is the surface area of the sphere? Round your answers to the nearest hundredth. 24 in2 a. What is the surface area of the cube? 5. CUBES Marcus builds a sphere inside of a cube. The sphere fits snugly inside the cube so that the sphere touches the cube at one point on each side. The side length of the cube is 2 inches. 0.015 4. THE ATMOSPHERE About 99% of Earth’s atmosphere is contained in a 31-kilometer thick layer that enwraps the planet. The Earth itself is almost a sphere with radius 6378 kilometers. What is the ratio of the volume of the atmosphere to the volume of Earth? Round your answer to the nearest thousandth. Surface Areas and Volumes of Spheres 12.57 in2 Chapter 12 DATE Word Problem Practice 1. ORANGES Mandy cuts a spherical orange in half along a great circle. If the radius of the orange is 2 inches, what is the area of the cross section that Mandy cut? Round your answer to the nearest hundredth. 12-6 NAME 5/30/09026_044_GEOCRMC12_890521.indd 3:09:21 PM 41 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 026_044_GEOCRMC12_890521.indd 40 Chapter 12 9. sphere: radius = 12.4 in. 7986.4 in3 8. sphere: circumference ≈ 36 yd 787.9 yd3 32 m 8578.6 m3 7. hemisphere: diameter = 18 mm 1526.8 mm3 5. Find the volume of each sphere or hemisphere. Round to the nearest tenth. 4. sphere: area of great circle ≈ 29.8 m2 119.2 m2 2 24,884.6 ft2 89 ft 3. hemisphere: radius of great circle = 8.4 in. 665.0 in 1. Find the surface area of each sphere or hemisphere. Round to the nearest tenth. 12-6 NAME Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Answers (Lesson 12-6) Enrichment 2.7 g/cm 19.32 g/cm3 11.35 g/cm3 10.50 g/cm3 Copper Iron Platinum 8.96 g/cm 7.874 g/cm3 21.45 g/cm3 3 3 A20 Glencoe Geometry 026_044_GEOCRMC12_890521.indd 42 Chapter 12 42 8. An aluminum ball and a lead ball each have a radius of 1.2 centimeters. Which weighs more? How much more? lead; 62.6 g 7. A silver ball and a copper ball each have a diameter of 3.5 centimeters. Which weighs more? How much more? silver; 34.6 g 6. An iron ball weighs 804 grams. Find the diameter of the ball to the nearest tenth of a centimeter. 5.8 cm 5. A lead ball weighs 326 grams. Find the radius of the ball to the nearest tenth of a centimeter. 1.9 cm Solve. Assume the balls are spherical. Round your answers to the nearest tenth. 4. a platinum ball with radius 0.7 cm 30.8 g 3. an aluminum ball with radius 3 cm 305.4 g 2. a gold ball 0.6 cm in diameter 2.2 g 1. a copper ball 1.2 cm in diameter 8.1 g Find the mass of each metal ball described. Assume the balls are spherical. Round your answers to the nearest tenth. Exercises The mass is about 2.81 grams. ≈ 10.5(0.27) ≈ 2.81 PERIOD Glencoe Geometry Find the mass of a silver ball that is 0.8 cm in diameter. 4 π(0.4)3 = 10.5 · − M=D·V Example To calculate the mass of a piece of metal, multiply volume by density. Aluminum Gold Lead Silver 3 The density of a metal is a ratio of its mass to its volume. For example, the mass of aluminum is 2.7 grams per cubic centimeter. Here is a list of several metals and their densities. DATE Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Spherical Geometry Study Guide and Intervention DATE PERIOD Name each of the following on sphere K. ) ( & * " + $ K ' % # 8 ; 5 7 3 F 6 −− ⎯, XU and SRT ⎯ and SV WT 9 : 4 2. ' ; ( & 3 M $ % −− ⎯ and EB ⎯, GC and GRZ AD " # V No 4. V No Chapter 12 43 Lesson 12-7 5/30/09 3:09:36 PM Glencoe Geometry Yes, the equator is a great circle. No other line of latitude is a great circle. 5. GEOGRAPHY Lines of latitude run horizontally across the surface of Earth. Are there any lines of latitude that are great circles? Explain. 3. Determine whether figure u on each of the spheres shown is a line in spherical geometry. 1. Name two lines containing point Z, a segment containing point R, and a triangle in each of the following spheres. Exercises AHI is a triangle on sphere K c. a triangle b. a line segment containing the point J −− ID is a segment on sphere K that contains the point J and BH are lines on sphere K that contain the point F EG a. two lines containing the point F Example where a plane is a flat surface made up of points that extends infinitely in all directions. In spherical geometry, a plane is the surface of a sphere. Geometry On A Sphere Up to now, we have been studying Euclidean geometry, 12-7 NAME 5/30/09026_044_GEOCRMC12_890521.indd 3:09:31 PM 43 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Chapter 12 Spheres and Density 12-6 NAME Answers (Lesson 12-6 and Lesson 12-7) Chapter 12 PERIOD Spherical Geometry Study Guide and Intervention (continued) DATE A21 N Glencoe Geometry Answers 44 Glencoe Geometry Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Spherical Geometry Skills Practice DATE PERIOD 6 * ) −− ⎯ and ⎯, SG, and STH SF IH 4 5 C ( ' , 2. " & L $ # % 5 −− ⎯ and ⎯, CA , and ATE BD ET , No V 4. Yes basketball V Chapter 12 45 No. Three lines divide the plane into 6 or 7 separate parts. 8. Three non-parallel lines divide the plane into 7 separate parts. Yes. The same statement works in spherical geometry. Lesson 12-7 6/2/09 4:48:36 PM Glencoe Geometry 7. Two lines meet at two 90° angles or they meet at angles whose sum is 180°. No. There are no parallel lines in spherical geometry. 6. If two lines meet a third line at the same angle, those lines are parallel. Yes. The same statement works in spherical geometry. 5. If two lines form vertical angles, then the angles are equal in measure. Tell whether the following postulate or property of plane Euclidean geometry has a corresponding statement in spherical geometry. If so, write the corresponding statement. If not, explain your reasoning. 3. Determine whether figure u on each of the spheres shown is a line in spherical geometry. 1. Name two lines containing point K, a segment containing point T, and a triangle in each of the following spheres. 12-7 NAME 045_055_GEOCRMC12_890521.indd 45 4/10/08 9:12:33 PM Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 026_044_GEOCRMC12_890521.indd 44 Chapter 12 Yes. The same statement works in spherical geometry. 6. A largest angle of a triangle is opposite the largest side. Yes. The same statement works in spherical geometry. 5. Three noncollinear points determine a triangle. No. There are no parallel lines in spherical geometry. 4. If two lines are perpendicular to a third line, they are parallel. No. There are no parallel lines in spherical geometry. 3. Given two parallel lines and a transversal, alternate interior angles are congruent. Yes. The same statement works in spherical geometry. 2. Given a line and a point on the line, there is only one perpendicular line going through that point. No. If two nonidentical lines intersect at a point, they intersect again on the opposite side of the sphere. 1. If two nonidentical lines intersect at a point, they do not intersect again. Tell whether the following postulate or property of plane Euclidean geometry has a corresponding statement in spherical geometry. If so, write the corresponding statement. If not, explain your reasoning. Exercises On the sphere to the right, if we are given line m we see that it goes through the poles of the sphere. If we try to make any other line on the sphere, it would intersect line m at exactly 2 points. This property is not true in spherical geometry. A corresponding statement in spherical geometry would be: “Given any line, there are no parallel lines.” Given any line, there are an infinite number of parallel lines. Example Tell whether the following postulate or property of plane Euclidean geometry has a corresponding statement in spherical geometry. If so, write the corresponding statement. If not, explain your reasoning. properties of Euclidean geometry are true in spherical geometry. Others are not true or are true only under certain circumstances. Comparing Euclidean and Spherical Geometries Some postulates and 12-7 NAME Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Answers (Lesson 12-7) Spherical Geometry Practice DATE PERIOD & , L % # ' ⎯ and AE ⎯, FA ⎯, ADE CB $ 5 " 2. 5 : M 9 ⎯ and ⎯, ZX ⎯ and TZK ZX TY ; A22 No tennis ball V 4. Yes V Glencoe Geometry 045_055_GEOCRMC12_890521.indd 46 Chapter 12 46 Glencoe Geometry The shortest route is to fly along the great circle connecting New York and Seattle, which crosses Canada. 9. AIRPLANES When flying an airplane from New York to Seattle, what is the shortest route: flying directly west, or flying north across Canada? Explain. Yes. The same statement works in spherical geometry. 8. All equilateral triangles are similar. Yes. The same statement works in spherical geometry. 7. Given a line and a point not on the line, there is exactly one line that goes through the point and is perpendicular to the line. No. The sum of the angles of a triangle is more than 180°. 6. The sum of the angles of a triangle is 180°. No. A triangle can have at most three obtuse angles. Tell whether the following postulate or property of plane Euclidean geometry has a corresponding statement in spherical geometry. If so, write the corresponding statement. If not, explain your reasoning. 5. A triangle can have at most one obtuse angle. 3. Determine whether figure u on each of the spheres shown is a line in spherical geometry. 1. , Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Spherical Geometry 7 C B Chapter 12 All three lines must intersect at two points. 4. GEOMETRY Three nonidentical lines on the circle divide it into either 6 sections or 8 triangles. What condition is needed so that the three lines form 6 sections? 137,900,000 square miles Source: NASA 3. OCEAN If the oceans cover 70% of Earth’s surface, what is the surface area of the oceans? 24,625,000 square miles Source: NASA 2. EARTH The Equator and the Prime Meridian are perpendicular great circles that divide Earth into North, South and East, West hemispheres. If Earth has a surface area of 197,000,000 square miles, what is the surface area of the North-East section of Earth? 6π − square feet D A 47 DATE PERIOD 138.3 miles Lesson 12-7 5/30/09 3:10:18 PM Glencoe Geometry b. Seattle, Washington, has coordinates (47°N, 122°W) and Portland, Oregon, has coordinates (45°N, 122°W). Estimate the distance between Portland and Seattle to the nearest tenth. 415.4 miles a. The mean radius of Earth is 3963 miles. Atlanta, Georgia, has coordinates (33°N, 84°W) and Cincinnati, Ohio, has coordinates (39°N, 84°W). Estimate the distance between Atlanta and Cincinnati to the nearest tenth. 5. GEOGRAPHY Latitude and longitude lines are imaginary lines on Earth. The lines of latitude are horizontal concentric circles that help to define the distance a place is from the equator. Lines of latitude are measured in degrees. The equator is 0°. The north pole is 90° north latitude. The lines of longitude are great circles that help to define the distance a place is from the Prime Meridan, which is located in England and considered the longitude of 0°. Word Problem Practice 1. PAINTING Consider painting quadrilateral ABCD on the beach ball with radius 1 ft. What is the surface area you would need to paint? 12-7 NAME 045_055_GEOCRMC12_890521.indd 47 6/2/09 4:46:23 PM Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Chapter 12 Name two lines containing point K, a segment containing point T, and a triangle in each of the following spheres. 12-7 NAME Answers (Lesson 12-7) Chapter 12 Enrichment 180˚ W DATE 90˚ W A23 0˚ 90˚ E PERIOD 60˚ N 40˚ N 20˚ N 0˚ 20˚ S 40˚ S 60˚ S 180˚ E Glencoe Geometry Answers 48 Glencoe Geometry Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Congruent and Similar Solids Study Guide and Intervention DATE PERIOD Corresponding angles are congruent Corresponding edges are congruent Corresponding faces are congruent Volumes are equal 8 2 4 in. 5 in. 3 in. 4 in. 8 in. 10 in. 6 in. 8 in. 2 cm Similar, 1:2 4 in. Similar, 1:5 1 cm Chapter 12 3. 1. 5 cm 10 cm 8 in. 49 4. 2. 2m Neither 2m Congruent 4.2 in. 4m 12.3 in. 1m 3m Lesson 12-8 5/30/09 3:10:33 PM Glencoe Geometry 1m 4.2 in. 12.3 in. Determine whether the pair of solids is similar, congruent, or neither. If the solids are similar, state the scale factor. Exercises The ratios of the corresponding sides are equal, so the triangular prisms are similar. The scale factor is 1:2. Since the scale factor is not 1:1, the solids are not congruent. 10 4 1 ratio of height: − =− 2 2 5 1 =− ratio of hypotenuse: − 8 4 1 ratio of length: − =− 2 3 1 ratio of width: − =− 6 Example Determine whether the pair of solids is similar, congruent, or neither. If the solids are similar, state the scale factor. • • • • Identify Congruent or Similar Solids Similar solids have exactly the same shape but not necessarily the same size. Two solids are similar if they are the same shape and the ratios of their corresponding linear measures are equal. All spheres are similar and all cubes are similar. Congruent solids have exactly the same shape and the same size. Congruent solids are similar solids with a scale factor of 1:1. Congruent solids have the following characteristics: 12-8 NAME 4/12/08045_055_GEOCRMC12_890521.indd 9:02:10 PM 49 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 045_055_GEOCRMC12_890521.indd 48 Chapter 12 Triangles, hexagons, prisms. 4. The Mercator projection uses a cylinder to map Earth, while the Lambert projection uses a cone to map Earth. What other shapes do you think could be used to map Earth? No. Lines of longitude become shorter as you travel towards the poles. 3. Does each square on the Lambert projection have the same surface area? Explain. No. Near the top, the width across is much smaller than the equator. 2. Does each square on the Mercator projection have the same surface area? Explain. To measure distances close to the equator. 1. When would it be useful to use a Mercator projection of Earth? The map on the right is a Lambert projection. When a pilot draws a straight line between two points on this map the line shows true bearing, or relative direction to the North Pole. However, the bottom area of this map distorts distances. The map on the right is a Mercator projection of Earth. On this map Greenland appears to be the same size as Africa. But Greenland has a land area of 2,166,086 square kilometers and Africa has a land area of 30,365,700 square kilometers. When making maps of Earth, cartographers must show a sphere on a plane. To do this they have to use projections, a method of converting a sphere into a plane. But these projections have their limitations. Spherical Geometry Projections 12-7 NAME Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Answers (Lesson 12-7 and Lesson 12-8) PERIOD Congruent and Similar Solids Study Guide and Intervention (continued) DATE 6 3 3 A24 2 ft 6 ft Glencoe Geometry 045_055_GEOCRMC12_890521.indd 50 Chapter 12 125π cubic in. 50 Glencoe Geometry 5. CONSTRUCTION A building company uses two similar sizes of pipes. The smaller size has a radius of 1 inch and length of 8 inches. The larger size has a radius of 2.5 inches What is the volume of the larger pipes? 12 in. 4. COMPUTERS A small rectangular laptop has a width of 10 inches and an area of 80 square inches. A larger and similar laptop has a width of 15 inches. What is the length of the larger laptop? 9:16 3. Two similar triangular prisms have volumes of 27 square meters and 64 square meters. What is the ratio of the surface area of the small prism to the surface area of the large prism? 1:64 2. Two similar cones have heights of 3 feet and 12 feet. What is the ratio of the volume of the small cone to the volume of the large cone? 9:64 1. Two cubes have side lengths of 3 inches and 8 inches. What is the ratio of the surface area of the small cube to the surface area of the large cube? Exercises So, the ratio of the volumes is 1:27. (1)3 a3 1 − = −3 or − 27 b3 (3) 1 . The scale factor is − 2 1 −− = − or − radius of the small sphere radius of the large sphere First, find the scale factor. Example Two spheres have radii of 2 feet and 6 feet. What is the ratio of the volume of the small sphere to the volume of the large sphere? If two similar solids have a scale factor of a:b then, • the ratio of their surface areas is a2:b2. • the ratio of their volumes is a3:b3. similar, certain properties are known. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Congruent and Similar Solids Skills Practice DATE PERIOD 2 cm congruent 5m 12 cm similar; 1:3 4 cm 3 cm 6 cm 9 cm 10 m 4. 2. 6 cm 3 ft 1 ft similar; 1:3 1 ft similar; 3:4 9 cm 3 ft 12 cm 9 ft 8 cm 3 ft Chapter 12 51 Lesson 12-8 6/1/09 10:25:58 AM Glencoe Geometry 7. COOKING Two stockpots are similar cylinders. The smaller stockpot has a height of 10 inches and a radius of 2.5 inches. The larger stockpot has a height of 16 inches. What is the volume of the larger stockpot? Round to the nearest tenth. 804.2 in3 3:2 6. Two similar cylinders have surface areas of 40π square feet and 90π square feet. What is the ratio of the height of the large cylinder to the height of the small cylinder? 64:343 5. Two similar pyramids have heights of 4 inches and 7 inches What is the ratio of the volume of the small pyramid to the volume of the large pyramid? 3. 1. Determine whether each pair of solids is similar, congruent, or neither. If the solids are similar, state the scale factor. 12-8 NAME 6/3/09 045_055_GEOCRMC12_890521.indd 11:22:33 PM 51 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Chapter 12 Properties of Congruent or Similar Solids When pairs of solids are congruent or 12-8 NAME Answers (Lesson 12-8) Chapter 12 Congruent and Similar Solids Practice DATE PERIOD 6 cm A25 4m 1m 24 cm 3m 5m 18 cm 4. 2. neither 2 cm 5 cm neither 5 cm 5 cm 12 cm 24 cm 1.5 cm 10 cm 10 cm 10 cm Glencoe Geometry Answers 52 Glencoe Geometry Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 15 cm 25 cm 25 cm Chapter 12 6144 cubic feet of grain 3. FARMING A farmer has two similar cylindrical grain silos. The smaller silo is 25 feet tall and the larger silo is 40 feet tall. If the smaller silo can hold 1500 cubic feet of grain, how much can the larger silo hold? 40 cm 15 cm 24 cm 2. MANUFACTURING Boxes, Inc. wants to make the two boxes below. How long does the second box need to be so that they are similar? 6.75 in. DATE 53 PERIOD 27:64 Lesson 12-8 5/30/09 3:10:59 PM Glencoe Geometry b. Find the ratio of the volume of MLB baseballs to the volume of NSA softballs. Round to the nearest tenth. 3:4 a. Find the ratio of the circumference of MLB baseballs to the circumference of NSA softballs. Source: MLB, NSA 5. BASEBALL Major League Baseball or MLB, rules state that baseballs must have a circumference of 9 inches. The National Softball Association, or NSA, rules state that softballs must have a circumference not exceeding 12 inches. 1.5:1 Source: NASA 4. PLANETS Earth has a surface area of about 196,937,500 square miles. Mars has a surface area of about 89,500,000 square miles. What is the ratio of the radius of Earth to the radius of Mars? Round to the nearest tenth. Congruent and Similar Solids Word Problem Practice 1. COOKING A cylindrical pot is 4.5 inches tall and has a radius of 4 inches. How tall would a similar pot be if its radius is 6 inches? 12-8 NAME 5/30/09045_055_GEOCRMC12_890521.indd 3:10:53 PM 53 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 045_055_GEOCRMC12_890521.indd 52 Chapter 12 1.6 square feet 7. ARCITHECTURE Architects make scale models of buildings to present their ideas to clients. If an architect wants to make a 1:50 scale model of a 4000 square foot house, how many square feet will the model have? 1:5.4 6. Two similar ice cream cones are made of a half sphere on top and a cone on bottom. They have radii of 1 inch and 1.75 inches respectively. What is the ratio of the volume of the small ice cream cone to the volume of the large ice cream cone? Round to the nearest tenth. 216:343 5. Two cubes have surface areas of 72 square feet and 98 square feet. What is the ratio of the volume of the small cube to the volume of the large cube? congruent 3m 4m 5m similar, 1:3 8 cm 3. 1 m 1. Determine whether the pair of solids is similar, congruent, or neither. If the solids are similar, state the scale factor. 12-8 NAME Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Answers (Lesson 12-8) Enrichment PERIOD 2 A26 Glencoe Geometry 045_055_GEOCRMC12_890521.indd 54 Chapter 12 54 16. It appears that if the dimensions of a solid are doubled, the volume is multiplied by . 8 15. The volume of the large sphere is how many times greater than the volume of the small sphere? 8 times 14. What is the volume of the large sphere? 288π m3 13. What is the volume of the small sphere? 36π m3 The large sphere at the right has twice the radius of the small sphere. 12. The volume of the large cube is how many times greater than that of the small cube? 8 times 11. What is the volume of the large cube? 1000 in3 10. What is the volume of the small cube? 125 in 3 9. How long are the edges of the large cube? 10 in. The sides of the large cube are twice the size of the sides of the small cube. Now consider how doubling the dimensions affects the volume of a cube. 8. It appears that if the dimensions of a solid are doubled, the surface area is multiplied by . 4 7. The surface area of the large sphere is how many times greater than the surface area of the small sphere? 4 times 6. What is the surface area of the large sphere? 144π m2 5. What is the surface area of the small sphere? 36π m2 The radius of the large sphere at the right is twice the radius of the small sphere. 4. The surface area of the large cube is how many times greater than that of the small cube? 4 times 3. What is the surface area of the large cube? 600 in2 2. What is the surface area of the small cube? 150 in 1. How long are the edges of the large cube? 10 in. The sides of the large cube are twice the size of the sides of the small cube. 3m 3m Glencoe Geometry 5 in. 5 in. Consider what happens to surface area when the sides of a figure are doubled. DATE 4/10/08 9:11:09 PM Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Chapter 12 Doubling Sizes 12-8 NAME Answers (Lesson 12-8) Chapter 12 Assessment Answer Key Quiz 1 (Lessons 12-1 and 12-2) Page 57 1. 4. 1. 156 cm3 2. 1005.3 cm3 8.6 m 2. 3. Quiz 3 (Lessons 12-4 and 12-5) Page 58 3. 120 units2 4. 1. C 2. G 3. D 4. F 5. D 261.8 cm3 201.1 m2 360 cm2 5. C B 5. Quiz 4 (Lessons 12-7 and 12-8) Page 58 Quiz 2 (Lessons 12-3 and 12-4) Page 57 −− ⎯⎯ and VU ⎯, ZX, WX and RSZ 1. 6. 1. 2 116.1 in 2. 3. 188.5 ft 2. similar, 2:1 2 7. 8. 92.8 units2 267.0 ft2 3. 1152 ft3 4. 5. yes 2827.4 in3 Chapter 12 4. 5. 27:125 9. 2884.0 in2 10. 150.8 in2 27:64 A27 Glencoe Geometry Answers Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Mid-Chapter Test Page 59 Chapter 12 Assessment Answer Key Vocabulary Test Page 60 Form 1 Page 61 1. 2. 1. slant height 2. similar solids right cylinder 3. 4. volume 5. axis 7. congruent solids true 10. 11. 12. false; oblique cone the sum of the areas of the lateral faces a prism whose lateral edges are also altitudes Chapter 12 13. D 14. H F 3. B 4. G 15. D 5. D 16. F 17. B 18. G 19. B 6. H 7. A 8. F true 9. G C false; pyramid 8. 12. 9. 10. 11. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 6. Page 62 B 20. H B: B A28 J 1020 ft2 Glencoe Geometry Chapter 12 Assessment Answer Key Form 2A Page 63 Page 64 12. D 1. 13. 2. 3. D 4. G C 15. 16. 17. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 6. 9. J 3. A 14. J 4. G 15. B 5. D 16. G 17. B 18. H 19. C 20. G B: 53 ft2 B F D F C F B 19. 20. 7. A 8. H B H 10. A G G B: 11. C 2. 9. 10. 13. H 18. F 8. H B 6. H 7. 12. A H 14. 5. H Page 66 391.6 ft2 11. B C Chapter 12 A29 Glencoe Geometry Answers 1. Form 2B Page 65 Chapter 12 Assessment Answer Key Form 2C Page 67 Page 68 1. 2. PQRS, PQT, QTR, RTS, PTS 12. 2 ft 13. 7690.6 ft3 14. 467.7 ft3 3. 15. 103.2 ft3 4. 120 cm2 16. 1140.4 cm2 5. 6 in2 17. 208.8 in3 18. 524.1 yd2 19. neither 20. 612.5 m2 B: 113.1 in2 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 6. great circle 6 in. 7. 270 in2 8. 9. 270 + 150 √ 3 in2 10. 62.8 ft2 11. 113.1 ft2 Chapter 12 A30 Glencoe Geometry Chapter 12 Assessment Answer Key Form 2D Page 69 Page 70 1. 2. 12. −− −− − −− −− −− GJ, HJ, IJ, GH, HI, GI 13. 14. 576 in3 923.6 cm3 2057 in3 3. 15. 750 in2 4. 258 ft2 5. 16. 17. 1592.8 in2 106.4 cm3 Lines in spherical 845.2 m2 geometry are great circles. Great circles always intersect, 7 ft 7. therefore they cannot be 18. 540 ft2 8. 19. 20. 11. similar 931.0 ft2 9. 10. parallel. Answers Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 6. 100.5 cm3 1562.5 ft3 204.2 cm2 282.7 cm2 Chapter 12 B: A31 201.1 in2 Glencoe Geometry Chapter 12 Assessment Answer Key Form 3 Page 71 Page 72 12. 184 cm3 13. 8m 1. 2. 3. It is a rectangle. 21 128 + 4 √ 2 units No, it will overflow. 4. 5. 35 + 7 √ 13 ft2 528 units2 14. 15. 16. 17,837.8 ft2 7. 32,435.2 ft2 468 in2 8. 9. 121.5 in3 3πr2 17. Yes; 33.5 cm3 < 37.7 cm3 19. similar 20. 1: √ 4 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 6. 148.4 in3 > 96 in3 No. Any three points on a sphere determine a triangle. 18. 842.1 in2 3 10. 233.8 in2 11. 387.7 in2 B: Chapter 12 A32 700 ft2 Glencoe Geometry Chapter 12 Assessment Answer Key Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Score General Description Specific Criteria 4 Superior A correct solution that is supported by well-developed, accurate explanations • Shows thorough understanding of the concepts of pyramids, prisms, cylinders, cones, spheres, surface area, lateral area, volume, and properties of solid figures. • Uses appropriate strategies to solve problems. • Computations are correct. • Written explanations are exemplary. • Figures and drawings are accurate and appropriate. • Goes beyond requirements of some or all problems. 3 Satisfactory A generally correct solution, but may contain minor flaws in reasoning or computation • Shows an understanding of the concepts of pyramids, prisms, cylinders, cones, spheres, surface area, lateral area, volume, and properties of solid figures. • Uses appropriate strategies to solve problems. • Computations are mostly correct. • Written explanations are effective. • Figures and drawings are mostly accurate and appropriate. • Satisfies all requirements of problems. 2 Nearly Satisfactory A partially correct interpretation and/or solution to the problem • Shows an understanding of most of the concepts of pyramids, prisms, cylinders, cones, spheres, surface area, lateral area, volume, and properties of solid figures. • May not use appropriate strategies to solve problems. • Computations are mostly correct. • Written explanations are satisfactory. • Figures and drawings are mostly accurate. • Satisfies the requirements of most of the problems. 1 Nearly Unsatisfactory A correct solution with no supporting evidence or explanation • Final computation is correct. • No written explanations or work shown to substantiate the final computation. • Figures and drawings may be accurate but lack detail or explanation. • Satisfies minimal requirements of some of the problems. 0 Unsatisfactory An incorrect solution indicating no mathematical understanding of the concept or task, or no solution is given • Shows little or no understanding of most of the concepts of pyramids, prisms, cylinders, cones, spheres, surface area, lateral area, volume, and properties of solid figures. • Does not use appropriate strategies to solve problems. • Computations are incorrect. • Written explanations are unsatisfactory. • Figures and drawings are inaccurate or inappropriate. • Does not satisfy requirements of problems. • No answer given. Chapter 12 A33 Glencoe Geometry Answers Extended-Response Test, Page 73 Scoring Rubric Chapter 12 Assessment Answer Key Extended-Response Test, Page 73 Sample Answers In addition to the scoring rubric found on page A33, the following sample answers may be used as guidance in evaluating open-ended assessment items. 1. The lateral area is the area of the lateral faces. The surface area includes the area of the lateral faces plus the areas of the two bases. 2. Oblique Right 3. Sample answer: Sam is painting the walls of a room. The room is 12 feet long, 10 feet wide, and 8 feet high. A gallon of paint covers 400 square feet and costs $16 per gallon. Find the cost of the paint needed to paint the room. 4. The first cylinder could have a radius of 3, a height of 4, a volume of 36π cubic units, and a surface area of 42π square units. The second cylinder could have a radius of 1, a height of 30, a volume of 30π cubic units, and a surface area of 62π square units. 5. 12 in. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 4 in. 4 in. 4 in. 4 in. 4 in. 16 • 12 The volume of the pyramid is − or 64 cubic units and 3 the volume of the prism is 4 • 4 • 4 or 64 cubic units. 6. The volume of the cylinder is πr2 • 2r. 3 2πr The volume of the hemisphere is − . 3 r The volume of the cone is πr • − 3 2 Therefore, the total volume is 3 3 2πr πr 2πr3 + − +− or 3πr3 cubic units. 3 Chapter 12 3 A34 Glencoe Geometry Chapter 12 Assessment Answer Key Standardized Test Practice Page 74 Page 75 9. A B C D F G H J 11. A B C D 12. F G H 10. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 2. F B G C H D J 3. A B C D 4. G H J F J 13. 5. A 6. F B G C H D J 1 4 0 0 0 0 0 1 1 1 1 1 2 2 2 2 2 3 3 3 3 3 4 4 4 4 4 5 5 5 5 5 6 6 6 6 6 7 7 7 7 7 8 8 8 8 8 9 9 9 9 9 14. 7. A 8. F B G Chapter 12 C H Answers 1. A 5 D J A35 0 0 0 0 0 1 1 1 1 1 2 2 2 2 2 3 3 3 3 3 4 4 4 4 4 5 5 5 5 5 6 6 6 6 6 7 7 7 7 7 8 8 8 8 8 9 9 9 9 9 Glencoe Geometry Chapter 12 Assessment Answer Key Standardized Test Practice Page 76 2.6 m 15. 25 16. 17. 18. 20. 21a. pentagonal pyramid 3141.6 in2 2206.2 cm2 13,684.8 m2 207.3 m b. c. d. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 19. 38.5 cm2 3421.2 m2 10,263.6 m2 Chapter 12 A36 Glencoe Geometry