∵CD∥AB
∴∠CDO+∠BOD=180°
∵∠CDO=60°
∴∠BOD=120°
∵OE平分∠DOB
∴∠DOE=½×120°=60°
∵OE⊥OF
∴∠EOF=90°
∴∠DOF=90°-60°=30°