Question

如图,OA⊥OB,OD平分∠BOC,OE平分∠AOC,试求∠DOE的度数.

Answer 1

∵OA⊥OB

∴∠AOB＝90

∴∠AOC＝∠AOB+∠BOC＝90+∠BOC

∵OE平分∠AOC

∴∠COE＝∠AOC/2＝（90+∠BOC）/2＝45+∠BOC/2

∵OD平分∠BOC

∴∠COD＝∠BOC/2

∴∠DOE＝∠COE-∠COD＝45+∠BOC/2-∠BOC/2＝45