7
Answer: CSet 3: Circles (Intermediate)
Explanation
PROBLEM
A circle has area 4pi. What is its radius?
A circle has area 4pi. What is its radius?
A.
3
B.
1
C.✓ Correct
2
D.
1
Detailed Explanation
Choice C is the best answer. A = pi times r squared. 4pi = pi times r squared. r squared = 4. r = 2
Why others are wrong:
A: 3 is incorrect because it does not satisfy the equation.
B: 1 is incorrect because it does not satisfy the equation.
D: 1 is incorrect because it does not satisfy the equation.