A circle has a radius of 48 milimeters.
What is the central angle in radians, that intercepts an arc of length 36π milimeters?
Circumference = pi * 2r The fraction of the total circumference will be 36pi/(pi*2r)
2 pi radians in complete circle
36 pi /(pi *2r) * 2 pi = 3pi/4 Radians