∵BO、CO分别平分∠ABC、∠ACB，∴∠OBC+∠OCB=1/2(∠ABC+∠ACB)=1/2(180°-∠A)=90°-1/2∠A，∴∠BOC=180°-(∠OBC+∠OCB)=90°+1/2∠A=110°。
