Geometry Essentials · Medium problem

Rays $OB$ and $OC$ lie in the interior of $\angle AOD$, in that order from $A$ to $D$. $m\angle AOB = 2x$, $m\angle BOC = 3x-4$, $m\angle COD = x+16$, and $m\angle AOD = 90^\circ$. Find $m\angle BOC$.