Chapter 4 Lesson 1-0 Points, Line Segments, Lines, and Rays NCTM Standards 1, 2, 3, 6, 7, 8, 9, 10 Common Core State Standards 4.G 1 Lesson Planner STUDENT OBJECTIVES • n To recognize, draw, and name points, rays, line segments, and lines • n To identify points, rays, line segments, and lines in two dimensional figures (CCRG p. CC 7) Open Ended Problem Solving / Headline Story Skills Practice and Review— Recognizing Multiples (CCRG pp. CC 8–CC 10) Introducing Points, Line Segments, Lines, and Rays (CCRG p. CC 8) • CCRG: Activity Masters, Connect the Dots, Memory Game Cards Points, Line Segments, Lines, and Rays (CCRG p. CC 9) • ruler or straightedge • LAB Masters, CCRG pp. CC 12–CC 13 Playing a Game: Memory (CCRG p. CC 10) (CCRG p. CC 11) Leveled Problem Solving (CCRG p. CC 11) Practice Master, CCRG p. CC 14 Intervention Activity (CCRG p. CC 11) Extension Master, CCRG p. CC 15 Extension Activity (CCRG p. CC 11) Lesson Notes Lesson 4.1-0 has been added. Use this lesson before Lesson 4.1. About the Lesson About the Mathematics This lesson introduces students to points, line segments, lines, and rays. These are the figures that they will encounter in the remaining lessons about angles, triangles, quadrilaterals, and parallel and perpendicular lines. Students are familiar with lines from their work with number lines. A line is a straight path of points that has no beginning or end. A line segment is a portion of a line that has two endpoints. A ray has one endpoint and extends forever in one direction. A point is an undefined term in mathematics. It has no size or shape, just position. Each of the figures that students will study in this lesson are made up of points. You may want to bring up the fact that, for example, even though a line segment generally only has its two endpoints labeled, it is made up of an infinite number of points between those endpoints. Students will name these figures according to the points they contain. It is not important right now for students to master this fact, but you may want to point out that AB is different from BA since the first letter in the name of a ray designates the endpoint. In the next lesson, students are introduced to angles. In this lesson, students are shown pictures of an angle and you may want to point out that an angle is made up of two rays that share an endpoint. CC 6 Common Core Resource Guide Chapter 4 • Lesson 1-0 Developing Mathematical Language Vocabulary: point, endpoint, line, line segment, ray A point is undefined. It is just a dot on the page with no size or shape, just position. A line is a straight path of points that has no beginning or end. A line segment is a portion of a line that has two endpoints. A ray is a portion of a line which has one endpoint and extends forever in one direction. Open-Ended Problem Solving Read the Headline Story to the class. Encourage students to solve the problem by drawing a picture and using information from the story. A.J. and Paulo each thought of a number. A.J.’s number is less than 10. Paulo’s number is greater than 10 but less than 50. When their numbers are multiplied the product is a multiple of 5. Beginning Draw a line segment, line, and ray on the board. Point to each and have students name them. Intermediate Draw a line segment, line, and ray. Point to each part of the figures and have students tell you what it represents. For example: the endpoints of the line segment, the endpoint of the ray, the arrows on the line. Advanced Name each figure and have students draw them on the board or on paper. Possible responses: The ones digit of the product must be 0 or 5. If AJ’s number is 5 then Paulo’s number could be any number between 10 and 50. If A.J.’s number is not 5 then Paulo’s number must be a multiple of 5. The largest product could be 9 3 45 or 405. Skills Practice and Review Recognizing Multiples Remind students that a multiple of 5 must end in either 0 or 5 (5, 10, 15, and so on.) Ask students what the possible ones digit could be for a multiple of 2. 0, 2, 4, 6, 8 Then ask what the possible ones digit could be for a multiple of 3. 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 What about a multiple of 4? 0, 2, 4, 6, 8 Common Core Resource Guide CC 7 TMG4CCRG_CH04_L1-0_TG_p06-p11.indd 7 12/28/10 11:04:43 AM Introducing Points, Line Segments, Lines, and Rays 20 MIN Materials • For the students: AM: Connect the Dots, ruler or straightedge • For the teacher: transparency of AM: Connect the Dots (optional) NCTM Standards 1, 2, 3, 6, 7, 8, 9, 10 CCSS 4.G 1 Concept Alert Up to this point students have probably referred to all straight paths as lines. Encourage them to use correct terminology when referring to line segments and rays. Rays will form the sides of angles and line segments will form the sides of twodimensional figures that they will study later in this chapter. Purpose To introduce students to the terms point, line, line segment, and ray and have them draw, identify, and name each of these figures Introduce Give students Activity Master: Connect the Dots. Display Activity Master: Connect the Dots or draw the points on the board. Tell students that the dot on the first line is called a point. Its name is A. Two points can be connected to form different figures. Use a ruler or straightedge to connect the second set of points and ask students to do the same. Tell them that this is a line segment. It has two endpoints. Write the name of this line segment, BC , next to the figure. Draw a line through the third set of points and put arrows at each end. Ask students to do the same. Tell them that this is a line. A line passes through the two points and extend in both directions forever. Write the name of this line, DE , next to the figure. Draw a ray through the last set of points and put an arrow at one end. Ask students to do the same. Tell them that this is a ray. A ray has one endpoint and extends forever in one direction. Write the Connect the Dots name of this ray, FG , next to this figure. Mention that points are usually named with capital letters. Name Date Activity Master Use a ruler to draw each figure. point A Task Ask students to find points, line segments, lines, and rays in the letters on the bottom of Activity Master: Connect the Dots. All of the letters in MATH are formed by connecting points with either lines, line segments, rays, or a combination of these figures. Help students to label the M with the names of the figures. You might also list the names of each figure that makes up the M: BC , DC , BA, and DE. • Do students demonstrate an ability to identify each of the figures? • Do students demonstrate an understanding of the labels attached to each figure? • Do students demonstrate an understanding that both segments and rays are portions of a line? B C line segment D E line F G ray Name the figures that each letter in the word MATH is made from. H D B A C G E F K I L M N O R P Q S T J M M is formed with two rays and two line segments A A is formed with three line segments T T is formed with a line and a ray H H is formed with three lines © School Specialty whole class line segments B D CC 16 Activity Master: Connect the Dots Common Core Resource Guide TMG4CCRG_CH04_L1-0_AM2_p16.indd 18 12/23/10 5:47 PM C E A rays Share Once students have had time to label the remaining letters ask them to share their findings with the class. Students can draw the figures on the board or label them on your transparency of Activity Master: Connect the Dots. Talk Math What makes a line segment different from a line? A line extends on forever in both directions. A line segment is part of a line and has two endpoints. Do you think a line named AB is the same figure as a line named BA? Possible answer: If A and B are the same points then the line that goes through them is the same line and you can name it both ways. CC 8 Common Core Resource Guide TMG4CCRG_CH04_L1-0_TG_p06-p11.indd 8 Chapter 4 • Lesson 1-0 12/28/10 11:04:45 AM Points, Line Segments, Lines, and Rays individuals LAB Masters, CCRG pp. CC 12–CC 13 Purpose To identify, name, and draw points, line segments, lines, and rays Lesson Activity Book Master, CCRG p. CC 12 Chapter 4 Lesson 1-0 20 MIN NCTM Standards 1, 2, 3, 6, 7, 8, 9, 10 CCSS 4.G 1 Lesson Activity Book Master, CCRG p. CC 13 Drawings will vary. Draw the following figures. Introducing Points, Line Segments, Lines, and Rays A. CD C. GH B. EF NCTM Standards 1, 2, 3, 4, 6, 7, 8, 9, 10 Common Core State Standards 4.G 1 IdentifyeachfigurethatcontainspointsXandY asalinesegment,line,oraray. G D E F H C A. Y B. C. Y X D. Y Use letters and symbols to name each figure shown. X X ray A. X Y line linesegment B. Q F. C. T S U P ray PQ E. X R RS TU G. Y X Y Challenge XY and XZ can meet at point X to make a straight line. ray © School Speciality linesegment Y linesegment © School Speciality X Y Z X What other figure could XY and XZ make? Draw that figure. Possible Answer: They could make an angle. Y X Drawings will vary. Common Core Resource Guide CC 12 Common Core Resource Guide TMG4CCRG_CH04_L1-0_LAB_p12-p13.indd 2 Z TMG4CCRG_CH04_L1-0_LAB_p12-p13.indd 3 12/23/10 6:17:17 PM CC 13 12/23/10 6:17:18 PM Teaching Notes for LAB Master, CCRG page CC 12 Teaching Notes for LAB Master, CCRG page CC 13 Students identify objects as line segments, lines, or rays. All figures have two named points X and Y. Students interpret the symbols given for figures and draw the corresponding figures. Students use the symbols for line segments, lines, and rays to name each figure. When drawing EF make sure students draw E as the endpoint of the ray. Differentiated Instruction Above Level For students who finish early, have them draw some real world objects and label line segments, lines, and rays in their drawings. Chapter 4 • Lesson 1-0 TMG4CCRG_CH04_L1-0_TG_p06-p11.indd 9 Challenge Problem This problem previews angles, which students will explore in the next lesson. Common Core Resource Guide CC 9 12/28/10 11:04:47 AM 15 MIN Materials • For each pair of students: Cards cut from AM: Memory Game Cards NCTM Standards 1, 2, 3, 6, 7, 8, 9, 10 CCSS 4.G 1 Concept Alert Check to be sure that students recognize that segments can make up some two-dimensional figures. For example, one card has a square on it that is made up of four segments. Another card pictures a circle with its diameter, which is a segment. Differentiated Instruction Basic Level If students are having a difficult time recognizing the figures on the cards have them lay out all of the cards face up and practice naming the figures with their partners. Once they have agreed which figures are on all of the cards they can flip them over and try the Memory game. Playing a Game: Memory Purpose To practice identifying line segments, lines, and rays Goal To find the most pairs of cards that match. Prepare materials. For each pair: Cut the cards out along the dotted lines on Activity Master: Memory Game Cards. How to Play Each pair of students should mix up the cards and place them in an array face down in front of them. Name Date Activity Master X Memory Game Cards Students take turns flipping over pairs of cards from the array to see if they can make a match. When students flip over each card they should state which figures are pictured. A match consists of any two cards that contain a matching figure. For example, a card might have a segment and another card might have a square—made up of four segments. This is a match. If the student finds a match they take that pair and take another turn. If not, the cards are flipped over again and the next student takes a turn. © School Specialty pairs Activity Master: Memory Game Cards CC 18 Common Core Resource Guide TMG4CCRG_CH04_L1-0_AM2_p17.indd 18 12/23/10 6:31:40 PM Since there are multiple ways of making matches with each card there may be two cards left in the array at the end of the game that do not match. The player with the most matching pairs once all of the possible matches have been made is the winner. Reflect and Summarize the Lesson True or false: A segment is contained in every line. True. A line is made up of an infinite number of points so you can identify two points as endpoints of a segment. CC 10 Common Core Resource Guide TMG4CCRG_CH04_L1-0_TG_p06-p11.indd 10 Chapter 4 • Lesson 1-0 12/28/10 11:04:49 AM Leveled Problem Solving Monica connected points P and Q with a straightedge. Basic Level She began at P and drew a line that ended at Q. What kind of figure did Monica draw? Explain. A segment. Monica made P and Q the endpoints of the segment. On Level She began at Q and drew a line that passed through P and did not stop at P. What kind of figure did Monica draw? Explain. A ray. The endpoint of the ray is Q. It passes through P and keeps going on forever. Practice Date Practice Master, CCRG p. CC14 Lesson 1-0 Name Points, Line Segments, Lines, and Rays Identify each figure that contains points X and Y as a line segment, a line, or a ray. X X Y ray line segment Z X 1. AB and CD N D A X C E D A B D Yes. The ray will extend straight past their endpoints. through segment AB. 3. AB and CD 4. AB and CD line segment MN M N © School Specialty Test Prep Angle DEF is made up of which two rays? A. ray ED and ray EF B. ray ED and ray EF C. ray DE and ray FR D. ray DE and ray FE B No. Line segments do not extend D E © School Specialty C D C Use a ruler or straightedge to draw each figure. ray AB B D ray line line CD A A B C 2. AB and CD B Y W line segment Decide whether or not each pair of figures will intersect. Write yes or no and explain your reasoning. line Y A Y Y B X When line segments, lines, or rays share one point they intersect. X Y Extension Date Extension Master, CCRG p. CC15 Lesson 1-0 Name Points, Line Segments, Lines, and Rays Above Level Monica added a point, R, above P. She connected these points with segments. What kind of figure did she draw? A triangle. A B C D A D B C No. Line segments do not extend No. These lines will not share any points no matter how far you extend past their endpoints. F them. CC 14 Common Core Resource Guide TMG4CCRG_CH04_L1-0_Practice_p14.indd 14 Common Core Resource Guide 12/23/10 4:42:28 PM TMG4CCRG_CH04_L1-0_Extension_p15.indd 15 CC 15 12/23/10 6:25:58 PM Intervention Activity Extension Activity Drawing Geometric Figures What’s My Angle? Write the name of several line segments, lines, and rays on the board. Have students draw each figure. You might use symbol notation, for example, AB , GH , DC , XY , ST , or you might write out the word, for example, ray AB. Draw three different angles with A as the vertex. B A B C B C A C A Ask students to use their own words to describe each figure. Possible answers: The straight angle can be described as a line. The right angle can be compared to the corner of a piece of paper. The acute angle looks like a piece of pie. Chapter 4 • Lesson 1-0 TMG4CCRG_CH04_L1-0_TG_p06-p11.indd 11 Common Core Resource Guide CC 11 12/28/10 11:04:52 AM Chapter 4 Lesson 1-0 Introducing Points, Line Segments, Lines, and Rays NCTM Standards 1, 2, 3, 4, 6, 7, 8, 9, 10 Common Core State Standards 4.G 1 Identify each figure that contains points X and Y as a line segment, line, or a ray. A. Y B. C. Y X D. Y X X X Y E. X F. G. Y X Y X Y © School Speciality CC 12 Common Core Resource Guide TMG4CCRG_CH04_L1-0_LAB_p12-p13.indd 2 12/28/10 2:06:55 PM Draw the following figures. A. CD C. GH B. EF Use letters and symbols to name each figure shown. A. B. Q R S C. T U P © School Speciality Challenge XY and XZ can meet at point X to make a straight line. Y X Z What other figure could XY and XZ make? Draw that figure. Common Core Resource Guide TMG4CCRG_CH04_L1-0_LAB_p12-p13.indd 3 CC 13 12/28/10 2:06:58 PM Name Practice Lesson 1-0 Date Points, Line Segments, Lines, and Rays Identify each figure that contains points X and Y as a line segment, a line, or a ray. X X Y Z X X Y X Y B D Y N Y Y W A X B E Use a ruler or straightedge to draw each figure. line CD ray AB line segment MN Angle DEF is made up of which two rays? A. ray ED and ray EF B. ray ED and ray EF C. ray DE and ray FR D. ray DE and ray FE CC 14 © School Specialty Test Prep D E F Common Core Resource Guide TMG4CCRG_CH04_L1-0_Practice_p14.indd 14 12/28/10 11:00:04 AM Name Extension Lesson 1-0 Date Points, Line Segments, Lines, and Rays When line segments, lines, or rays share one point they intersect. A Decide whether or not each pair of figures will intersect. Write yes or no and explain your reasoning. AB and CD C B D AB and CD B A B A D C D C © School Specialty AB and CD AB and CD A B C D A D B C Common Core Resource Guide TMG4CCRG_CH04_L1-0_Extension_p15.indd 15 CC 15 12/28/10 12:30:46 PM Name Activity Master Date Connect the Dots Use a ruler to draw each figure. point A B C line segment D E line F G ray Name the figures that each letter in the word MATH is made from. A H D B C G E F K I L M N O R P Q S T J M A T CC 16 © School Specialty H Common Core Resource Guide TMG4CCRG_CH04_L1-0_AM2_p16.indd 18 12/23/10 5:47 PM Name Date Activity Master © School Specialty Memory Game Cards CC 17 Common Core Resource Guide TMG4CCRG_CH04_L1-0_AM2_p17.indd 17 12/23/10 6:32:29 PM