以∠AOB的顶点O为端点引射线OC,使∠AOC=5∠BOC,OD是∠AOB平分线,若∠AOB=72°

问题描述:

以∠AOB的顶点O为端点引射线OC,使∠AOC=5∠BOC,OD是∠AOB平分线,若∠AOB=72°
求∠COD的度数.谢啦,

∠AOC-∠BOC=∠AOB
5∠BOC-∠BOC=72
4∠BOC=72
∠BOC=18
∠COD=18+36=54