The area of the circle is about 227 m2.

COURSE 2 LESSON 8-4COURSE 2 LESSON 8-4

Find the area of the circle to the nearest unit.

= (8.5)2 Substitute 8.5 for the radius.

A = r 2 Use the formula for the area of a circle.

= 226.9798775 Use a calculator.

227 Round the solution to the nearest unit.

8-4

Circumferences and Areas of Circles

The area of the pizza is approximately 615.8 cm2.

COURSE 2 LESSON 8-4COURSE 2 LESSON 8-4

A pizza has a diameter of 28 cm. What is the area of the

pizza? Round to the nearest tenth.

= 615.75164 Use a calculator.

615.8 Round the solution to the nearest tenth.

= (14)2 Substitute 14 for the radius.

A = r 2 Use the formula for the area of a circle.

r = = 14 The radius is half the diameter.28

2

8-4

Circumferences and Areas of Circles

Use 3.14 for . Find the area and the circumference of each circle to the nearest tenth.

1. r = 10 m 2. d = 14 ft

COURSE 2 LESSON 8-4COURSE 2 LESSON 8-4

A = 314 m2; C = 62.8 m A = 153.9 ft2; C = 44.0 ft

8-4

Circumferences and Areas of Circles