49. As shown in the figure, $A D / / B C$, point $O$ is on $A D$, $B O, C O$ bisect $\angle A B C, \angle D C B$ respectively, if $\angle A+\angle D$ $=240^{\circ}$, then $\angle B O C=$ $\qquad$ ${ }^{\circ}$.
answer: 120