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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Try these problems on your own.

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

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

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

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

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 = sq in. 8 in.

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

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

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

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

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 = sq in. 17 in.