8

Set 3: Circles (Intermediate)

Explanation

Answer: A

PROBLEM

Recent studies show that a circle has radius 3. What is the arc length of a 90-degree sector? (Express as a number times pi)

A circle has radius 3. What is the arc length of a 90-degree sector? (Express as a number times pi)

A.

1.5pi

✓ Correct
B.

6pi

C.

2.5pi

D.

3pi

Detailed Explanation

[Variation 1] Choice A is the best answer. Arc length = (90/360) times 2 times pi times 3 = 1.5pi

Why others are wrong:
B: 6pi is incorrect because it does not satisfy the equation.
C: 2.5pi is incorrect because it does not satisfy the equation.
D: 3pi is incorrect because it does not satisfy the equation.