证明：∵∠ACB＝90∴∠BAC+∠B＝90∵CD⊥AB∴∠BAC+∠ACD＝90∴∠ACD＝∠B∵AE平分∠BAC∴∠BAE＝∠CAE∵∠CEF＝∠B+∠BAE，∠CFE＝∠ACD+∠CAE∴∠CEF＝∠CFE
