Answer
$10$, $126.9^\circ$
Work Step by Step
Use the figure given in the exercise, we can identify the coordinates of the end point as $(-6,8)$, the magnitude of the vector can be found as $|\vec v|=\sqrt {(-6)^2+(8)^2}=10$. The angle $\theta=180^\circ-atan(\frac{8}{6})\approx126.9^\circ$
