6

Set 1: Circles (Advanced)

Explanation

Answer: B

PROBLEM

A circle has radius 4. What is the area of a 90-degree sector? (Express as a number times pi)

A circle has radius 4. What is the area of a 90-degree sector? (Express as a number times pi)

A.

8pi

B.

4pi

✓ Correct
C.

16pi

D.

8pi

Detailed Explanation

Choice B is the best answer. Sector area = (90/360) times pi times 4 squared = 4pi

Why others are wrong:
A: 8pi is incorrect because it does not satisfy the equation.
C: 16pi is incorrect because it does not satisfy the equation.
D: 8pi is incorrect because it does not satisfy the equation.