3

Set 5: Circles (Intermediate)

Explanation

Answer: C

PROBLEM

Recent studies show that a circle has radius 7. What is the arc length of a 120-degree sector? (Express as a number times pi)

A circle has radius 7. What is the arc length of a 120-degree sector? (Express as a number times pi)

A.

7pi

B.

5.666666666666666pi

C.

4.666666666666666pi

✓ Correct
D.

14pi

Detailed Explanation

[Variation 1] Choice C is the best answer. Arc length = (120/360) times 2 times pi times 7 = 4.666666666666666pi

Why others are wrong:
A: 7pi is incorrect because it does not satisfy the equation.
B: 5.666666666666666pi is incorrect because it does not satisfy the equation.
D: 14pi is incorrect because it does not satisfy the equation.