2

Set 1: Circles (Advanced)

Explanation

Answer: B

PROBLEM

A circle has radius 3. What is the area of a 180-degree sector? (Express as a number times pi)

A circle has radius 3. What is the area of a 180-degree sector? (Express as a number times pi)

A.

6pi

B.

4.5pi

✓ Correct
C.

9pi

D.

9pi

Detailed Explanation

Choice B is the best answer. Sector area = (180/360) times pi times 3 squared = 4.5pi

Why others are wrong:
A: 6pi is incorrect because it does not satisfy the equation.
C: 9pi is incorrect because it does not satisfy the equation.
D: 9pi is incorrect because it does not satisfy the equation.