Central angle of a circle

The length of arc is given by $c=\dfrac{\theta}{360}(2\pi r)$ , where $r$ is the radius and $\theta$ is the central angle in degrees. Substituting into the formula, we have

$32=\dfrac{\theta}{360}(2)(\pi)(20)$ $\implies$ $\theta=\dfrac{32(360)}{2\pi (20)}=\dfrac{288}{\pi}$

We know that $360^\circ=2\pi$ , so we convert

$\theta=\dfrac{288}{\pi}\left(\dfrac{2\pi}{360}\right)=\boxed{1.6}$