Set 2: Circles (Advanced)

**Choice B is the best answer.** Arc = (angle/360) times 2 times pi times r. 2pi = (angle/360) times 6pi. angle = 120 degrees

Explanation

Answer: B

PROBLEM

A circle has radius 3 and an arc length of 2pi. What is the central angle in degrees?

122

120

✓ Correct

121

240

Detailed Explanation

Choice B is the best answer. Arc = (angle/360) times 2 times pi times r. 2pi = (angle/360) times 6pi. angle = 120 degrees

Why others are wrong:

A: 122 is incorrect because it does not satisfy the equation.

C: 121 is incorrect because it does not satisfy the equation.

D: 240 is incorrect because it does not satisfy the equation.