Question

The radius of a circle is 3 cm. What is the measure in radians of the angle subtended by an arc 21pi/8 cm long

Answer 1

7pi/8

Explanation:

Well the arc is 21pi/8 cm. Our formula to find the length of arc is r × theta(angle). Let's take the angle as x.

R × x = 21pi/8

x = 21pi/8 ÷ R = 21pi/8 ÷ 3 = 7pi/8 rad