Find radian measure of an angle

[RPMACS]

Find radian measure of and angle at the center of a circle with a radius of 12cm and intercepts an arc of 15cm on circle.
I can't figure out how to draw this and enter into an equation.

 

[Deleted member 4993]

Find radian measure of and angle at the center of a circle with a radius of 12cm and intercepts an arc of 15cm on circle.
I can't figure out how to draw this and enter into an equation.

\(\displaystyle \theta = \frac{S}{r}\)

where

S = lrngth of arc

r = radius of the circle