Got Your Back 5c. Students will be able to find the area of triangles and parallelograms.

Transcription

1 Got Your Back 5c Students will be able to find the area of triangles and parallelograms.

2 Lesson Objective: Students will be able to find the area of triangles and parallelograms. Materials -Worksheet: A Limber Leader -Captain s Challenge Workbook CA State Standards / Common Core: 5 MG 1.1 CST Released Test Question(s) (February 2009 Grade 5) # Ruler Guided Practice: 1. Draw two rectangles on the board that will fit the proportions of the measurements below. 2. Label two sides of Rectangle A as 7inches and 8inches and the two sides of Rectangle B as 9inches and 3 inches. 3. Write the formula for finding the area of a rectangle on the board. 4. Select two volunteers to come and each find the area of a rectangle for the class. 5. Have the class help students solve the problems on the board. 6. Remind students that answers for area problems need to be given in square units. 7. Now draw a dotted line through each of the rectangles and ask students what two new shapes you just created inside the rectangle. (Two triangles) 8. Have students reason why the formula for the area of a triangle would be half that of a rectangle. (Students should say that a triangle only fits into half of a rectangle so the area will only be half as much as a rectangle.) 9. Select two new volunteers to come to the board and find the area of a triangle that was created inside of the rectangles on the board. 10. Have the class help students solve the problems on the board. 11. Then draw two parallelograms on the board that each resembles the size of a rectangle already on the board. 12. Have students tell you the differences between the rectangles and parallelograms. Students should notices that the parallelogram has slanted lines on both sides and rectangle has straight lines. CONTINUED ON NEXT PAGE

3 13. Ask students if they think the area formula for a parallelogram will be different than that of a rectangle. Students should come to the conclusion that because both shapes will have the same area formulas because the parallelogram s slanted sides are equal allowing the shape to have the same formula as a rectangle. 14. Before moving on ask students if they have any questions about finding the area of triangles or parallelograms. 15. Hand out the Got Your Back Worksheet a. Remind students that you will be doing the Anaheim Ducks section together as a class, and to wait for instructions before beginning the worksheet. b. Also, remind students that all written responses need to be in complete sentences. 16. Direct students to look at the Anaheim Ducks chart, and to not begin the worksheet just yet. a. Discuss the information given in the chart as a class, asking the following questions: i. What unit of measure was used to find each player s score? inches ii. What letter represents Ryan Getzlaf s stretch? g iii. What letter represents John Gibson s stretch? h" iv. What letter represents Francois Beauchemin s stretch? b 17. Use Parallelograms A and B to answer questions #1-5 together as a class. 18. Check to make sure that students understand the concepts presented and have filled in the first part of the worksheet correctly before moving on the independent activity.

4 Independent Activity 1. Divide students into teams of three. 2. Each group will need to choose a team name, e.g., My Team: The Power Plays 3. Have each student write their name and the other group member s names inside the boxes on the chart. 4. Have each group member complete the Heads-Up exercise, recording each score in the chart and rounding to the nearest inch. 5. Have students work together to answer questions #6-9. Remind students that they need to round their answers to the nearest inch. 6. As a group, for #10, each team needs create a word problem that reflects their data, like #5 from the Anaheim Ducks data. The problem can focus on the area of a parallelogram, triangle, or both shapes. 7. Once the team has created a problem also have them solve it. 8. Walk around the room once the activity begins to help insure students correctly complete the activity and ask students questions to guide them if they are in need of help. 9. Once every team has completed #6-10 have teams share their word problems (#10) and have the other groups solve them. Extension For advanced students and/or for extra practice: Have students follow the Overtime instructions listed at the bottom of the worksheet. For English Learners and/or students in special education, here are some suggested vocabulary terms to help preview and reinforce throughout the lesson: - half - formula - area

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6 27 inches squared 54 inches squared 24 inches squared 48 inches squared 11 and 10 inches

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