1. Over Lesson 11–5 A.A B.B C.C D.D 5-Minute Check 1 Find the measure of all angles. Over Lesson 11-4 141 3x 54 2x

2. Splash Screen

3. Then/Now You found the area of rectangles. (PSSA Survivor) Find areas of parallelograms and triangles. Find areas of trapezoids.

4. Vocabulary base altitude The base of a parallelogram or a triangle is any side of the figure from which we measure the height. The bases of a trapezoid are the parallel sides. A line segment that is perpendicular to the base of a figure with endpoints on the base and the side opposite that base. Often called the height.

5. Concept A

6. Example 1 A Find Areas of Parallelograms A. Find the area of the parallelogram. The base is 3 meters. The height is 3 meters. A=bhArea of a parallelogram A=3 ● 3Replace b with 3 and h with 3. A=9Multiply. Answer: The area is 9 square meters.

7. Example 1 B Find Areas of Parallelograms B. Find the area of the parallelogram. Estimate A = 4 × 6 or 24 The base is 4.3 inches. The height is 6.2 inches. A=bhArea of a parallelogram A=4.3 ● 6.2Replace b with 4.3 and h with 6.2. A=26.66Multiply. Answer: The area is 26.66 square inches. This is close to the estimate.

8. A.A B.B C.C D.D Example 1 CYP A A.6 cm 2 B.7 cm 2 C.12 cm 2 D.14 cm 2 A. Find the area of the parallelogram.

9. A.A B.B C.C D.D Example 1 CYP B A.0.975 ft 2 B.1.95 ft 2 C.2.8 ft 2 D.5.6 ft 2 B. Find the area of the parallelogram.

10. Concept B

11. Example 2 A Find Areas of Triangles A. Find the area of the triangle. Answer: The area of the triangle is 6 square meters. The base is 3 meters. The height is 4 meters. Area of a triangle Replace b with 3 and h with 4. Multiply 3 × 4 = 12. Simplify.

12. Example 2 B Find Areas of Triangles B. Find the area of the triangle. The base is 3.9 feet. The height is 6.4 feet. Area of a triangle Replace b with 3.9 and h with 6.4. Estimate

13. Example 2 B Find Areas of Triangles Answer: The area of the triangle is 12.48 square feet. Multiply 3.9 × 6.4. Simplify. Check12.48 ≈ 12

14. A.A B.B C.C D.D Example 2 CYP A A.180 in 2 B.90 in 2 C.27 in 2 D.13.5 in 2 A. Find the area of the triangle.

15. A.A B.B C.C D.D Example 2 CYP B A.4.4 cm 2 B.8.8 cm 2 C.9.36 cm 2 D.18.72 cm 2 B. Find the area of the triangle.

16. Concept C

17. Example 3 Find Areas of Trapezoids PLAYROOM The floor of a playroom is shaped like a trapezoid. Use the figure to find the area of the playroom. Estimate

18. Example 3 Find Areas of Trapezoids Area of a trapezoid Simplify inside parentheses.

19. Example 3 Find Areas of Trapezoids Simplify. Answer: The area of the trapezoid is square meters. Divide out the common factors. Check

20. A.A B.B C.C D.D Example 3 CYP A.20 ft 2 B.30 ft 2 C.40 ft 2 D.60 ft 2 Find the area of the trapezoid.

21. End of the Lesson