Find the length of the arc intercepted on the unit circle by the following central angle 7pi/4

Question

A) 7pi/2

B) 11pi/4

C) 7pi/4

D) pi

Answer 1

c) is correct

the arc length = radius times the angle when measured in radians

L=radius x radians = 1 x 7pi/4 = 7pi/4

another way to look at it is 7pi/4 is almost 2pi which is the length of the circumference = pid = 2pir = 2pi(1) = 2pi = 8pi/4. 7pi/4 is almost 8pi/4

none of the other choices are close to 2pi. c) has to be the best answer, and as it turns out, it's the exact answer.