解:设∠AOC=x,则∠BOC=2x,∴∠AOB=3x,∵OD平分∠AOB,∴∠AOD=∠DOB=∠AOB=x,∴∠COD=x﹣x=19°,∴x=38°,∴∠AOB=3x=114 °
A.35°B.55°C.70°D.110°
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