## Precalculus (10th Edition)

$810^\circ.$
To convert from radians to degrees, the answer in degrees must be multiplied by $\frac{180^\circ}{\pi}$. Therefore: $\frac{9\pi}{2}\text{radians}=\frac{9\pi}{2}\cdot\frac{180^\circ}{\pi}=810^\circ.$