Arcs of a circle Geometry and angles If a central angle of measure $30°$ is subtended by a circular arc of length $6\,\mathrm{m}$, how many meters in length is the radius of the circle?
A. $\frac{π}{36}$
В. $\frac{1}{5}$
С. $π$
D. $\frac{36}{π}$
E. $180$


How do I find out what the radius length of the angle is? The answer is (D) by the way.

Length of the arc is $L_\alpha = \alpha r$, so $r = \frac {L_\alpha}\alpha = \frac 6{\pi/6} = \frac {36}\pi$
