ANSWERS: (1) D = 2r

D = 2 x 6 inches

D = 12 inches

(2) C = 2 π r

C = 2 x 3.14 x 6 inches

C = 37.68 inches

REVIEW OF RADIUS, DIAMETER, AND CIRCUMFERENCE

Solve the following:

(1) What is the radius of a circle

if the diameter equals 15 inches?

(2) What is the radius of a circle

if the circumference equals 18.8499

inches? HINT: C = 2 π r (Solve for

r.)

(3) The radius of a circle = 10

feet. What is the circumference?

C = 2 π r

(4) The diameter of a circle 20

feet. What is the circumference?

C = π D

(5) If the radius = 15 feet, the

diameter must equal ___________ feet.