Tetrahedral Kite Unit Contents I. II. III. IV. V. Teacher Notes a. Tissue Paper Template b. Tetrahedron Net c. Square Pyramid Net d. Octahedron Net Outline of Lessons MYP Unit Planner Student Handout titled Tetrahedral Kite Project Rubrics * Project adapted from Illuminations: Tetrahedral Kites (2010) http://illuminations.nctm.org/LessonDetail.aspx?id=L639 and Tetrahedron Kites (2008) http://gw011.k12.sd.us/Tetrahedron%20Kites.htm Tetrahedral Kite Teacher Notes Necessary Materials: eight-inch straws kite string or yarn glue stick or transparent tape tissue paper (20 in. x 26 in.) cardstock tissue template (attached to this document) scissors and rulers nets for tetrahedron, octahedron, and square pyramid (attached to this document) Time Required: Four weeks of geometry and measurement lessons (see the lesson plan outline) Two to three days of kite construction and flying the kite Two to three days for students to do measurements and complete the handouts One day for class discussion and summary ________________________________________________________________ This project is intended for seventh graders that are more advanced in mathematics and are currently taking Pre-Algebra. However, it can be modified to meet the needs of grade level students. I would eliminate the relationship table and generalization of the patterns for grade level students or I would give them a lot more guidance in the process. Introducing the Project: This project should be introduced prior to any lessons on geometry and measurement. When you introduce the project you should begin by describing the purpose (this is given on the first page of the student handout). I would also describe the tetrahedron as a solid with four vertices and four sides, all of which are equilateral triangles. Next, I would give an example of where the tetrahedron shape is seen in nature, such as in chemistry. The tetrahedron shape is seen in covalent bonds of molecules. For instance in a methane molecule (CH4) the four hydrogen atoms, surround the carbon atom with tetrahedral symmetry. It helps to draw or show a picture of the molecule so the students get a better since of its configuration. Teacher Notes 1 You should also approach the topic of the tetrahedral kite from a more historical perspective by discussing the significance of Alexander Bell’s kites. “Bell's pioneering work with the tetrahedral form led to a number of applications. The use of the tetrahedral in the structure of large kites, some of them big enough to carry a person aloft, was remarkable. His experimentation with the tetrahedron was used in construction projects (a tower on his property at Beinn Breagh in Cape Breton, N.S. and other structures) as well as in kite framing. Some of the sketches in his notebooks of tetrahedral design ideas show how enamored he was with the utility and strength of the tetrahedron as a three dimensional structure.” (http://bestbreezes.squarespace.com/alexander-graham-bell-tetrah/) Image available at http://best-breezes.squarespace.com/alexander-graham-belltetrah/, May 9, 2010 Teacher Notes 2 Constructing the Kite: Put the students into groups of four. Each student will be in charge of building one tetrahedron needed for the large tetrahedron kite. Before the students are given the instructions to building the kite have the students work in groups on the “What is a Tetrahedron” handout. This will give the students a better sense of what they will be building. If you will need the students to bring materials for the kite, make sure you tell them several days in advance. Place all of the materials in an area of the room that is easily accessible so that the students can go and get what they need. The students will need to read the written instructions and use the pictures for direction in building their kite. Monitor and provide help as they work individually on their single tetrahedron. Make sure to emphasize tying good knots to create tight joints. This is usually difficult for the students. They can get help from other group members, but each student is responsible for making their own tetrahedron. Make sure the students are following the instructions as you walk around monitoring them. Show the students how to fold the tissue paper in half four times. You will need to print the tissue paper template on cardstock or heavy weight paper. Provide enough copies for each group. Have the students cut out the template. Model where to place the template on the folded tissue paper and then show them where to cut. This can be tricky for the students and they might have to do it more than once. Another part that is difficult for the students is attaching the bridle. The bridle is one or more strings attached to the spine, which help control the kite in the air. Having a completed exemplar in the classroom that has a bridle attached is very helpful. The instructions become easier to understand when they can see the actual bridle on the kite. If you use the provided rubric then you will need to provide an opportunity for the students to fly the kite. This is the part of the project that the students enjoy the most. Developing the Volume Relationship: Discovering linear and surface area relationships are typically easier for the students, especially when working in groups. However, the volume relationship is not as obvious. This is when I would show the students the nets for the tetrahedron, octahedron, and square pyramid. Have four groups build the tetrahedron, one group build the octahedron and two groups build the square pyramid all from the nets. It works better to have the nets on cardstock or other heavyweight paper. The octahedron group might need help folding and taping Teacher Notes 3 their net together. When the figures are built, show how they all have the same edge length. Then show how you can build the large tetrahedron from four single tetrahedrons and one octahedron. This will help verify that the open space in the middle of the kite is an octahedron. Now it will be necessary to show that the volume of the octahedron is four times the volume of the single tetrahedron. The best way to demonstrate this is by presenting the octahedron as two square pyramids. Then discuss how the volume of the square pyramid is double the volume of the single tetrahedron. This is easier for the students to see. You are now ready to summarize the kite (the group tetrahedron) in terms of the single tetrahedron. Hopefully, the students will have a better grasp as to why the volume of the group tetrahedron is equivalent to eight times the volume of the single tetrahedron. Length, Area, and Volume Table: It is important to discuss what the units are for on the table. Tell the students that they will not use the actual measurements they got from the previous handout. Now they are looking at the edge as one single unit. This might take some time for them to grasp so don’t be surprised if you have to explain it several times. They do not have a tetrahedron built with an edge length of three, so this will require them to find their answers based on the relationships and not on an actual model. It is possible to construct a tetrahedron with an edge length of four by using four copies of the kite (the group tetrahedron). They could look at this model to help them fill in the table. Teacher Notes 4 Tissue Paper Template PLACE ALONG FOLD PLACE ALONG FOLD Image created by Pamela Cordova, May 1, 2010 Teacher Notes 5 Tetrahedron Net Image available at http://www.learner.org/interactives/geometry/print_tetrahedron.html, May 9, 2010 Teacher Notes 6 Square Pyramid Net Image created by Pamela Cordova, May 1, 2010 Teacher Notes 7 Octahedron Net Image available at http://www.learner.org/interactives/geometry/print_octahedron.html, May 9, 2010 Teacher Notes 8 Outline of Lessons for Tetrahedral Kite Project This outline consists of seventeen geometry and measurement lessons that are necessary to cover prior to the completion of the project. The Tetrahedral Kite Project is meant to serve as a summative assessment for the measurement concepts of area, surface area and volume. Many of these lessons contain prerequisite skills that are essential for the students to be able to do in order to classify, create, and measure their shapes. I. Spatial Thinking a. Points, Lines, and Planes i. define, name and identify points, lines, planes, segments, rays, parallel lines, and perpendicular lines b. Angles i. define and indentify adjacent, vertical, congruent, supplementary, complementary, acute, right, obtuse and straight angles ii. draw and find the measure of angles iii. find the measure of angles based on angle relationships c. Classifying Polygons i. classify triangles and quadrilaterals by their sides and angles ii. define and indentify regular polygons iii. name polygons based on their number of sides d. Congruence i. define congruence ii. identify corresponding parts iii. find the measure of angles and sides based on congruence e. Circles i. explore and discuss the value of pi ii. define what a circle is and define the parts of a circle: radius, diameter, circumference, and chord II. Perimeter and Area a. Measuring in Customary Units i. measure lengths of segments using inches and feet ii. write customary units as fractions, mixed numbers and decimals b. Perimeter i. define perimeter ii. walk the perimeter of an irregular shape for kinesthetic learners iii. measure and find the perimeter of regular and irregular polygons iv. develop formulas for the perimeter of rectangles and regular polygons Outline of Lessons 1 c. Circumference i. define circumference ii. develop the circumference formula iii. find the circumference of circles given the radius or diameter d. Area: Parallelograms i. define area and square units ii. indentify the height and base of rectangles and parallelograms iii. develop the area of a parallelogram formula iv. measure and find the area of rectangles and parallelograms e. Area: Triangles and Trapezoids i. discover the relationship between parallelograms and triangles ii. develop the area of a triangle formula iii. identify the base and height of a triangle iv. measure and find the area of triangles using the formula f. Area: Circles i. discover the formula for area of a circle by the relating it to a parallelogram ii. review the order of operations as it pertains to exponents iii. measure and find the area of circles using the formula g. Area: Regular and Irregular Polygons i. deconstruct a figure with 5 or more sides into shapes on the formula chart, such as triangles and rectangles ii. measure and find the area of a regular hexagon by adding the areas of the composite shapes iii. measure and find the area of an irregular pentagon by adding the areas of the composite shapes III. Surface Area and Volume a. Space Figures and Nets i. define and classify three dimensional figures ii. create nets and match nets with their corresponding solids b. Volume: Prisms and Cylinders i. define volume, base area, and height of the prism ii. develop the formulas for volume of prisms and cylinders iii. measure and find the volume of prisms and cylinders using a formula c. Surface Area: Prisms and Cylinders i. define surface area and lateral area ii. find the surface area of prism and cylinders using their nets iii. discover the formulas for surface area of prisms and cylinders from studying the net and matching the parts to the formula iv. measure and find the surface area of prisms and cylinders using a formula Outline of Lessons 2 d. Volume: Cones and Pyramids i. discover the relationship between a prism and pyramid with the same height and base ii. develop the formula for the volume of a cone and a pyramid iii. measure and find the volume of cones and pyramids using a formula e. Surface Area: Cones and Regular Pyramids i. define slant height ii. discover the formula for the lateral area and then surface area of a regular pyramid using slant height and a net iii. develop the formula for the lateral area and then surface area of cone by comparing it to the lateral area of a regular pyramid and substituting circumference for perimeter iv. measure and find the surface area of cones and regular pyramids using a formula Outline of Lessons 3 MYP unit planner Unit title Tetrahedral Kite Teacher(s) Pamela Cordova Subject and grade level Mathematics, Year 2 Time frame and duration 5 to 6 weeks Stage 1: Integrate significant concept, area of interaction and unit question Area of interaction focus Significant concept(s) Which area of interaction will be our focus? Why have we chosen this? What are the big ideas? What do we want our students to retain for years into the future? Human Ingenuity In this unit students will build a tetrahedral kite. It will lead students to examine the process of building something larger from something small. Enrich student understanding of measurable attributes of geometric objects. Discover relationships between linear, area, and volume measures of similar figures. MYP unit question How do we build? Assessment What task(s) will allow students the opportunity to respond to the unit question? What will constitute acceptable evidence of understanding? How will students show what they have understood? The assessment task is the tetrahedral kite project that contains real-life problems and investigations. Students will build a kite, measure and find different attributes of the kite, and MYP Unit Planner 1 discover relationships for similar figures. Which specific MYP objectives will be addressed during this unit? Knowledge and Understanding Know and demonstrate understanding of concepts from geometry Select and apply general rules correctly to solve problems including those in real-life contexts Investigating Patterns Recognize patterns Describe patterns as relationships or general rules Justify or prove mathematical relationships and general rules Which MYP assessment criteria will be used? Criterion B (Investigating Patterns) Stage 2: Backward planning: from the assessment to the learning activities through inquiry Content What knowledge and/or skills (from the course overview) are going to be used to enable the student to respond to the unit question? What (if any) state, provincial, district, or local standards/skills are to be addressed? How can they be unpacked to develop the significant concept(s) for stage 1? Name and classify different geometrical elements. Finding the area and volume of regular and irregular two-dimensional and three-dimensional shapes. TEKS addressed: 8.5A – predict, find, and justify solutions to application problems using tables and algebraic equations 8.7B – use geometric concepts and properties to solve problems in fields such as architecture 8.8A – find lateral and total surface area of pyramids using concrete models 8.8C – estimate measurements and use formulas to solve application problems involving lateral and total surface area and volume 8.10A – describe the resulting effects on perimeter and when dimensions are changed proportionally 8.10B – describe the resulting effect on volume when dimensions of a solid are changed proportionally 8.16A – make conjectures from patterns or sets of examples and nonexamples MYP Unit Planner 2 TAKS addressed: Objective 2 (Patterns, Relationships and Algebraic Reasoning) Objective 3 (Geometry and Spatial Reasoning), Objective 4 (Measurement), and Objective 6 (Underlying Processes and Mathematical Tools) Week 1: Introduce the project to the students by describing the purpose. Discuss the historical relevance of the tetrahedral kite by describing Alexander Bell’s kites. Also show them that the tetrahedron shape can be found in nature, mainly in chemistry. Put them into groups of four or allow them to choose groups of four and ask each group to bring the required materials needed to build the kite if you cannot provide it for them. Weeks 1, 2, 3 and 4: Unpacking – Lessons on geometry concepts such as spatial thinking, classifying polygons and solids, perimeter, circumference, area, surface area and volume. Weeks 5 and 6: Students will build and fly the kites during class time. They will also answer the questions on the handouts, fill in the relationship table, and summarize their findings. Approaches to learning How will this unit contribute to the overall development of subject-specific and general approaches to learning skills? Collaboration – the students work in groups and this requires them to delegate and take responsibilities, adapt to roles, and resolve group conflicts Thinking – student must apply knowledge and concepts of surface area and volume in a logical progression and discover relationships Transfer – make connections across mathematics, chemistry and history Learning experiences Teaching strategies How will students know what is expected of them? Will they see examples, rubrics, templates? How will we use formative assessment to give students feedback during the unit? How will students acquire the knowledge and practice the skills required? How will they practice applying these? Do the students have enough prior knowledge? How will we know? Students will review exemplars and rubrics in order to understand what is expected of them. There are two rubrics, one for the kite and one for investigating the patterns. MYP Unit Planner What different teaching methodologies will we employ? How are we differentiating teaching and learning for all? How have we made provision for those learning in a language other than their mother tongue? How have we considered those with special educational needs? Formative Assessments – Homework will be collected and graded. Feedback is then given to the students about the work. Classroom discussions will allow students to summarize and examine their findings. The students will also be observed by the 3 Students will acquire knowledge by classroom lessons that include class discussions, student-led discoveries, notetaking and teacher modelling. They will practice these skills by doing homework and they will receive feedback for improvement. Students will apply the knowledge they learned in the lessons in order to classify and find the volume and surface area of their tetrahedron. The students need to have basic measuring skills, such as how to use the ruler. The students will do exercises during the lessons to establish if they do have these basic skills. If they are lacking the skills it will be addressed during the lessons. teacher as they work in groups on their project. They will be given guidance if they are not on the right track. Teaching Methodologies – During the geometry and measurement lessons students will receive direct instruction. The lessons will also involve inquiry based learning when students are asked to discover relationships between linear, area, and volume measures. Project-based learning is a substantial part of this unit. Differentiation – The formative assessments described above allowed for exploration of different learning styles and for individual differentiated instruction during class or tutoring. Special education colleagues, ESL teachers, and counsellors are available for assistance in differentiated instruction. Resources What resources are available to us? How will our classroom environment, local environment and/or the community be used to facilitate students’ experiences during the unit? Materials for tetrahedral kite project: eight-inch straws, kite string or yarn, glue sticks, tissue paper (20 in. by 26 in), scissors and rulers. Tissue paper template printed on cardstock or heavy weight paper. The nets for the tetrahedron, octahedron, and square pyramid printed on cardstock or heavy weight paper Websites: http://best-breezes.squarespace.com/alexander-graham-bell-tetrah/ http://gw011.k12.sd.us/buildingkite.htm http://illuminations.nctm.org/LessonDetail.aspx?ID=L639 Textbooks: Holt, Algebra 1 Prentice Hall, Texas Pre-Algebra MYP Unit Planner 4 Name: ______________________________ Tetrahedral Kite Project The purpose of this project is to enrich your understanding of measurable attributes of geometric objects. During this project you will work in groups to build an attractive tetrahedral kite. You will also discover relationships between linear, area, and volume measures of similar figures. Unit Question: How do we build? Content Question: What are the relationships between linear, area, and volume measures of similar figures? AoI: Human Ingenuity TEKS: 8.5A, 8.7B, 8.8A, 8.8C, 8.10A, 8.10B, 8.16A Materials for each group: eight-inch straws kite string or yarn glue stick or transparent tape tissue paper (20 in. x 26 in.) cardstock tissue template scissors and rulers Elements of the project: Tetrahedral Kite (one per group) Project Booklet – any handouts and tables completed for this project will be bound together in a booklet with a cover page (one per group) Image available at http://www.ellisoneducation.com/images/ellison_lessons/large/tetrahedron_kites_ lg.jpg Due Date: ___________________ * Project adapted from Illuminations: Tetrahedral Kites (2010) and Tetrahedron Kites (2008) http://gw011.k12.sd.us/Tetrahedron%20Kites.htm Student Handouts 1 What is a Tetrahedron? Is the tetrahedron a prism, cylinder, pyramid or cone? _____________________ What is the base(s) of the figure? ________________________________ Classify the tetrahedron according to the following: A. Number of vertices ____________________ B. Number of faces ____________________ C. Number of edges ____________________ All faces of the tetrahedron are what type of triangle? ___________________ You will be making tetrahedrons for your kite. How many straws will you need to build one single tetrahedron? ____________________ It will take four small tetrahedrons to build one large tetrahedron kite. How many straws will you need to build the large tetrahedron kite? ____________________ Student Handouts 2 Instructions for Building a Singe Tetrahedron You will be working in groups. Optimally, they will be groups of four so that each group member is in charge of building a single tetrahedron. 1. Send a member of your group to collect the string and number of straws you will need to build four tetrahedrons. Distribute the straws evenly. 2. Each group member will need to cut one piece of string about 40 inches long and another string that is about 20 inches long. 3. Place 3 straws on the 40 inch string and tie a knot to make a tight triangle with one long string end very long and the other end shorter. (The easiest way to pass the string through the straw is to feed the string through one end and then suck the string out through other end.) Tetrahedron Kites (2008) 4. Place two straws on a 20 inch string and tie them tightly to the corners of the triangle that do NOT have the original knot. The five straws should now form a rhombus with one diagonal, as show below. Tetrahedron Kites (2008) 5. Place one straw on the long end of the original 40 inch string and tie it tightly to the opposing vertex of the other equilateral triangle. Connect A to B as shown in the picture below. Tetrahedron Kites (2008) Student Handouts 3 6. Now you have a tetrahedron. Make sure the joints are tight and do not trim the excess string, as it will be used later. Tetrahedron Kites (2008) 7. One group member will fold a 20” x 26” piece of tissue paper in half 4 times, short end to short end. 8. Place the cardstock tissue template on the folded corner of the tissue paper and cut along the three sides marked CUT. Tetrahedron Kites (2008) 9. Your group should now have four tissue pieces, which look like the picture below when unfolded. This is enough for one whole kite. However, if you want a multi-colored kite, fold and cut more tissue. Tetrahedron Kites (2008) Student Handouts 4 10. One tissue will cover 2 faces of each tetrahedron. Lay the tissue paper on the table. Put glue on the flaps, and fold the flaps over the straws. Rotate the tetrahedron, apply glue to the other flaps, and fold these flaps over the straws. Tetrahedron Kites (2008) The resulting tetrahedron will be referred to as “single tetrahedron”. Instructions for Building the Large Tetrahedron 1. Using the strings at each vertex, tie the four single tetrahedrons together in a larger tetrahedron as shown below. Make the joints tight with no slack in the string for a sturdier model. Tetrahedron Kites (2008) The resulting larger tetrahedron will be referred to as “group tetrahedron”. Attaching the Bridle The bridle is one or more strings attached to the spine, which help control the kite in the air. 1. Cut a piece of string about 35” long and tie a loop knot at its center as shown below. Image available at http://pages.swcp.com/~nmmc/climbrocks/knots/figure8.GIF, May 9, 2010 Student Handouts 5 2. Tie one of the loose ends of the string to the top of your kite at point A. Tie the other end to point B, as shown in the figure below. Try to get the loop centered between points A and B. A B Image available at http://rsntoystore.com/images/tetra_large.JPG, May 9, 2010 3. Cut a second length of string about 20” long. Tie one end of the string to the kite at point C, as shown in the figure below. Thread the other end through the loop knot and tie at point D. All strings should be drawn tight when pulling out on the loop knot. C D Image available at http://rsntoystore.com/images/tetra_large.JPG, May 9, 2010 Launching and Flying 1. 2. 3. 4. Attach your flying string to the loop knot. The kite requires no tail for stable flight (if the kite is well constructed). Set the kite on the ground with the bridle up. Walk away from the kite about 40 feet into the wind letting out flying string as you go. If there is enough wind, the kite will lift and soar into the air. 5. Remember to keep tension on the line. Student Handouts 6 Measurement and Relationship Questions Edge Length 1. Measure the edge length of the single tetrahedron in centimeters. __________________ 2. Measure the edge length of the group tetrahedron in centimeters. __________________ 3. What is the relationship between the edge lengths? ___________________________________________________________ 4. Write the simplified ratio of the edge length of the single tetrahedron to the edge length of the group tetrahedron. __________________ Area of One Face 5. Measure and find the area of one face of the single tetrahedron. Write the formula and show your work in a complete and logical manner. ___________________________________________________________ ___________________________________________________________ ___________________________________________________________ Area = __________________ 6. Compare one face of the single tetrahedron to one face of the group tetrahedron. Describe what you see. ___________________________________________________________ ___________________________________________________________ 7. Now find the area of one face of the group tetrahedron. __________________ Student Handouts 7 Surface Area 8. Find the surface area of the single tetrahedron. Describe the process you used to find the surface area. ___________________________________________________________ ___________________________________________________________ Surface Area of single tetrahedron = __________________ 9. Find the surface area of the group tetrahedron. Describe the process you used to find the surface area. ___________________________________________________________ ___________________________________________________________ Surface Area of group tetrahedron = __________________ 10. What is the relationship between the surface areas? ___________________________________________________________ 11. Write the simplified ratio of the surface area of the single tetrahedron to the surface area of the group tetrahedron. __________________ Volume 12. Measure and find the volume of the single tetrahedron. Write the formula and show your work in a complete and logical manner. ___________________________________________________________ ___________________________________________________________ ___________________________________________________________ Volume of single tetrahedron = __________________ Student Handouts 8 13. Measure and find the volume of the group tetrahedron. Write the formula and show your work in a complete and logical manner. ___________________________________________________________ ___________________________________________________________ ___________________________________________________________ Volume of group tetrahedron = __________________ 14. What is the relationship between the volumes? ___________________________________________________________ 15. Write the simplified ratio of the volume of the single tetrahedron to the volume of the group tetrahedron. __________________ Student Handouts 9 Length, Surface Area, and Volume Table In this table we will define length, area, and volume as follows: The edge length of the single tetrahedron is one unit The face area of the single tetrahedron is one unit triangle (the area is in terms of triangles) The volume of the single tetrahedron is one unit tetrahedron (the volume is in terms of tetrahedrons) Edge Length Area of a Face Surface Area Volume 1 1 (one triangle) 4 (four triangles) 1 (one tetrahedron) 2 4 3 4 5 6 7 8 100 n Student Handouts 10 Summing it Up 1. Write a summary of what you found regarding the relationships between linear, area, and volume measures of similar figures. ___________________________________________________________ ___________________________________________________________ ___________________________________________________________ ___________________________________________________________ ___________________________________________________________ ___________________________________________________________ 2. How you can validate these claims? Give examples that support your summary. ___________________________________________________________ ___________________________________________________________ ___________________________________________________________ ___________________________________________________________ ___________________________________________________________ 3. Based on what you learned in class or by doing research, where is the tetrahedron shape seen in nature or real-life? ___________________________________________________________ ___________________________________________________________ 4. Make suggestions of how this learning experience could be improved. ___________________________________________________________ __________________________________________________________ Student Handouts 11 Kite Rubric Criteria Construction of the kite 0 Did not follow instructions 1 Poorly constructed Does it fly? No Yes 2 Suitably constructed 3 Skillfully constructed so that all the joints are tight and the kite is visually appealing Total Score ______ / 4 Patterns and Relationships Rubric (based on MYP Mathematics Criterion B) Achievement Level Descriptor Level 0 Did not do any work 1-2 Can do simple problems, like finding the surface area and volume, with help from the teacher 3-4 Can find simple relationships and patterns, and suggest how they work 5-6 Can find relationships and patterns, describe how they work, and write the rules of the patterns 7-8 Can find relationships and patterns, describe how they work, write the rules of the patterns, and explain why the rules work and show proof Total Score ______ / 8 Rubrics 1