Answer
$-450^\circ.$
Work Step by Step
To convert from radians to degrees, the measurement in radians must be multiplied by $\frac{180^\circ}{\pi}$.
Therefore
$\frac{-5\pi}{2}\text{radians}=\frac{-5\pi}{2}\cdot\frac{180^\circ}{\pi}\\=-450^\circ.$
