6

Set 2: Circles (Intermediate)

Explanation

Answer: D

PROBLEM

A circle has circumference 4pi. What is its radius?

A circle has circumference 4pi. What is its radius?

A.

3

B.

4

C.

1

D.

2

✓ Correct

Detailed Explanation

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

Why others are wrong:
A: 3 is incorrect because it does not satisfy the equation.
B: 4 is incorrect because it does not satisfy the equation.
C: 1 is incorrect because it does not satisfy the equation.