In a circle, an arc of length 8 pi cm is intercepted by a central angle of 2 pi/3 radians. What is the radius of the circle?

Question

In a circle, an arc of length 8 pi cm is intercepted by a central angle of 2 pi/3 radians. What is the radius of the circle?

Answer 1

x/360 * pi * D = 8 * pi

x/360 * D = 8

x * D = 8 * 360

BUT x = 2*pi/3 is given

2 * pi/3 * D = 8 * 360

D = 8 * 360 * 3 / (2*pi)

= 8640/*2 * pi)

= 4320/pi

R = 2160/pi