8

Set 2: Circles (Intermediate)

Explanation

Answer: D

PROBLEM

A circle has circumference 8pi. What is its radius?

A circle has circumference 8pi. What is its radius?

A.

2

B.

2

C.

8

D.

4

✓ Correct

Detailed Explanation

Choice D is the best answer. C = 2 times pi times r. 8pi = 2 times pi times r. r = 4

Why others are wrong:
A: 2 is incorrect because it does not satisfy the equation.
B: 2 is incorrect because it does not satisfy the equation.
C: 8 is incorrect because it does not satisfy the equation.