,∵∠BOD=2∠AOB即∠BOD∶∠AOB=2∶1 ∴∠BOD=2/3∠AOD ∵OC平分∠AOD ∴∠DOC=1/2∠AOB ∴∠BOD-∠DOC=∠BOC 即2/3∠AOD-1/2∠AOD=17° ∠AOD=17°÷(2/3-1/2) =17°÷1/6 =102°
