设∠BOC=x,∠°显然,∠AOC+∠COD+∠AOD=360°,
又,∠AOC+∠COD+∠AOD=∠AOC+∠BOD-∠BOC+∠AOD
=150°+150°-x+3x=300°+2x
所以300°+2x=360°,得x=30°