∠AOС= ∠AOB + ∠BOC = 180°
∠AOB=∠BOC+30°
∠BOC+∠BOC +30°= 180°
2∠BOC= 180°-30°
∠BOC= 150°:2=75°
∠AOB=∠BOC+30°=75° +30°= 105
∠AOС= ∠AOB + ∠BOC = 180°
∠AOB=∠BOC+30°
∠BOC+∠BOC +30°= 180°
2∠BOC= 180°-30°
∠BOC= 150°:2=75°
∠AOB=∠BOC+30°=75° +30°= 105