∠AOB=3∠DOC∠AOB=∠AOC+∠BOD-∠DOC所以∠AOC+∠BOD-∠DOC=3∠DOC而∠AOC=60°，∠BOD=90°所以∠DOC=35°
110
157.5 360=AOC+BOD+AOB+DOCAOB=3DOCAOB+DOC=360-60-904DOC=210DOC=52.5AOB=3DOC=3x52.5=157.5
请问图呢？
