Set 5: Circles (Intermediate)

[Variation 1] **Choice C is the best answer.** A = pi times r squared. 64pi = pi times r squared. r squared = 64. r = 8

Explanation

Answer: C

PROBLEM

Recent studies show that a circle has area 64pi. What is its radius?

A circle has area 64pi. What is its radius?

✓ Correct

Detailed Explanation

[Variation 1] Choice C is the best answer. A = pi times r squared. 64pi = pi times r squared. r squared = 64. r = 8

Why others are wrong:

A: 4 is incorrect because it does not satisfy the equation.

B: 10 is incorrect because it does not satisfy the equation.

D: 16 is incorrect because it does not satisfy the equation.