∠AOC=3∠BOD
∠AOB-∠COB=3(∠COD-∠COB)
60°-∠COB=3(45°-∠COB)
60°-∠COB=135°-3∠COB
3∠COB-∠COB=135°-60°
2∠COB=75°
∠COB=75°/2=37.5°
∠AOD=∠AOB+∠BOD
=∠AOB+∠COD-∠COB
=60°+45°-37.5°
=67.5°
∠AOC=3∠BOD
∠AOB-∠COB=3(∠COD-∠COB)
60°-∠COB=3(45°-∠COB)
60°-∠COB=135°-3∠COB
3∠COB-∠COB=135°-60°
2∠COB=75°
∠COB=75°/2=37.5°
∠AOD=∠AOB+∠BOD
=∠AOB+∠COD-∠COB
=60°+45°-37.5°
=67.5°