因为∠A=70°所以∠ABC+∠ACB=180-∠A=180-70=110因为BO平分∠ABC所以∠OBC=∠ABC/2，同理∠OCB=∠ACB/2所以∠OBC+∠OCB=(∠ABC/2+∠ACB/2)=(∠ABC+∠ACB)/2=110/2=55°所以∠BOC=180-(∠OBC+∠OCB)=180-55=125°
