Question

已知OA平分∠BOD,OC平分∠AOB,∠COD=75°求∠AOB的度数

Answer 1

∠COD=∠COA+∠AOD=75°

2(∠COA+∠AOD)=150°

2∠COA+∠AOD+∠AOD=150°

∠BOD+∠AOD=150°

3∠AOD=150°

∠AOD=50°

∠COA=∠COD-∠AOD=75°-50°=25°

∠AOB=2∠AOC=2*25°=50°