证明：∵CE⊥AB，∠ACB=90°，∴∠CEB=90°，∴∠ACE+∠BCE=90°，∠B+∠BCE=90°，∴∠B=∠ACE，∵FD∥BC，∴∠B=∠ADF=∠ACE，∵AF平分∠CAB，∴∠CAF=∠DAF，在△ACF和△ADF中∠CAF＝∠DAFAF＝AF∠ACF＝∠ADF，∴...