因原题无图,故分类讨论,请要参考符合题意的①若点C在∠AOB内,设∠AOC=X,则∠BOC=5X,X+5X=90,X=15°∴∠BOC=75°,∴∠BOD=15°（A在∠COD外）或∠BOD=165°（A在∠COD内）②若点C在∠AOB外,设∠AOC=3X,则∠BOC=5X,5...