Answer
$-10\pi$
Work Step by Step
RECALL:
To convert an angle in degrees to radians, multiply $\dfrac{\pi}{180^o}$ then simplify.
Thus, converting the given angle to radians gives:
$\require{cancel}
-1800^o
\\= -1800^o \cdot \dfrac{\pi}{180^o}
\\= -\cancel{1800^o}^{10} \cdot \dfrac{\pi}{\cancel{180^o}}
\\=-10\pi$
