6
Answer: CSet 3: Circles (Intermediate)
Explanation
PROBLEM
A circle has area 49pi. What is its radius?
A circle has area 49pi. What is its radius?
A.
5
B.
14
C.✓ Correct
7
D.
8
Detailed Explanation
Choice C is the best answer. A = pi times r squared. 49pi = pi times r squared. r squared = 49. r = 7
Why others are wrong:
A: 5 is incorrect because it does not satisfy the equation.
B: 14 is incorrect because it does not satisfy the equation.
D: 8 is incorrect because it does not satisfy the equation.