1. Lesson 10-5 Pages 520-525 Area: Parallelograms, Triangles, and Trapezoids Lesson Check 10-4

2. What you will learn! How to find the area of parallelograms, triangles, and trapezoids.

3. BaseAltitude

4. What you really need to know! The area A of a parallelogram equals the product of its base b and its height h. A = bh BASE (b) HEIGHT (h)

5. The area of a parallelogram is the same as the area of a rectangle!

6. What you really need to know! The area A of a triangle equals half the product of its base b and height h. A = ½bh BASE (b) Height (h)

7. The area of a triangle is the same as ½ the area of a parallelogram!

8. What you really need to know! The area A of a trapezoid equals half the product of the height h and the sum of the bases a and b. A = ½ h(a+b) a b h

9. Notice how the top layer and bottom layer of the trapezoids creates the base of the parallelogram! The area of a trapezoid is the same as ½ the area of a parallelogram!

10. h h a b

12. Example 1: Find the area of the parallelogram. A = bh A = 3 x 3 A = 9 m 2

13. Example 2: Find the area of the parallelogram. A = bh A = 6.2 x 4.3 A = 26.66 in 2

14. Example 3: Find the area of the triangle. A = ½ bh A = ½ x 3 x 4 A = 6 m 2

15. Example 4: Find the area of the triangle. A = ½ bh A = ½ x 3.9 x 6.4 A = 12.48 ft 2

16. Example 5: Find the area of the trapezoid.

17. A = ½ h(a+b) A = ½ x 6(7 ½ + 5 ¼ ) A = 38 ¼ m 2

18. Example 6: A wall that needs to be painted is 16 feet wide and 9 feet tall. There is a doorway that is 3 feet by 8 feet and a window that is 6 feet by 5 ½ feet. What is the area to be painted?

19. Area of wall Area of doorway Area of window A = bh A = 16 x 9 A = 144 A = bh A = 3 x 8 A = 24 A = bh A = 6 x 5 ½ A = 33 Area to be painted is: 144 – 24 – 33 = 87 ft 2

20. Page 523 Guided Practice #’s 3-6

22. Pages 520-523 with someone at home and study examples! Read:

23. Homework: Pages 524-525 #’s 8-22 even, 24-28, 32-43 Lesson Check 10-5

28. Page 749 Lesson 10-5

29. Lesson Check 10-5