做CF⊥AD的延长线交于F∵AC平分∠BAD(∠BAF)CE⊥AB,CF⊥AF∴CE=CF,在Rt△ACF和Rt△ACE中CF=CEAC=AC∴Rt△ACF≌Rt△ACE∴AF=AE∵∠ADC+∠ABC=180°∠ADC+∠FDC=180°∴∠ABC=∠FDC即∠EBC=∠FDC在Rt△BCE和Rt△CDF中C...