3. Definition: Rectangle A rectangle is a quadrilateral with four right angles.

4. Area: Rectangle L = Length W = Width Area = L x W sq units L W

5. Example: Rectangle Area = 9 ft x 3 Area = 27 sq ft 3 ft 9 ft

6. Definition: Square A square is a quadrilateral with four congruent sides and four right angles.

7. Area: Square S = Length of each side Area = S x S sq units S

8. Example: Square Area = 8 cm x 8 Area = 64 sq cm 8 cm

9. Definition: Triangle A triangle is a polygon with three sides.

10. Area: Triangle B = Base H = Height Area = ½ B x H sq units B H B H

11. Example: Triangle Area = ½ x 12 ft x 6 Area = 36 sq ft 12 ft 6 ft

12. Definition: Trapezoid A trapezoid is a quadrilateral with only two sides parallel.

13. Area: Trapezoid B1 = Base 1 B2 = Base 2 H = Height Area = ½ x (B1 + B2) x H sq units B2 B1 H

14. Example: Trapezoid Area = ½ x (4m + 8m) x 5 m Area = 30 sq m 8 m 5 m 4 m

15. Definition: Circle A circle is a set of all points in a plane that are an equal distance from its center.

16. Area: Circle r = radius Area =  r 2 sq units r

17. Example: Circle Area =  r 2 sq units   3.14 Area = 3.14 x (6 in.) 2 Area = 3.14 x 36 sq in. Area = 113.04 sq in. 6 in.

18. Try these problems on your own.

19. Find the area of the rectangle below. Area = 7 ft x 5 ft Area = 35 sq ft 5 ft 7 ft

20. Find the area of the square below. Area = 11 cm x 11 cm Area = 121 sq cm 11 cm

21. Find the area of the figure below. Area = ½ x 9 ft x 4 ft Area = 18 sq ft 9 ft 4 ft

22. Find the area of the figure below. Area = ½ x (7m + 11m) x 6 m Area = 54 sq m 11 m 6 m 7 m

23. Find the area of the circle below. Area =  r 2 sq units   3.14 Area = 3.14 x (8 in.) 2 Area = 3.14 x 64 sq in. Area = 200.96 sq in. 8 in.

24. Find the area of the rectangle below. Area = 2.7 ft x 4.5 ft Area = 12.15 sq ft 2.7 ft 4.5 ft

25. Find the area of the square below. Area = 6.5 cm x 6.5 cm Area = 42.25 sq cm 6.5 cm

26. Find the area of the figure below. Area = ½ x 7.8 ft x 3.1 ft Area = 12.09 sq ft 7.8 ft 3.1 ft

27. Find the area of the figure below. Area = ½ x (3.6m + 8.4m) x 6.2 m Area = 37.2 sq m 8.4 m 6.2 m 3.6 m

28. Find the area of the circle below. Area =  r 2 sq units   3.14 Area = 3.14 x (17 in.) 2 Area = 3.14 x 289 sq in. Area = 907.46 sq in. 17 in.