∵四边形ABCD为平行四边形∴AB∥CD,∠BAD=∠DCB∴∠ABF=∠CDE∵AF平分∠BAD,CE平分∠DCB∴∠BAF=1/2∠BAD =1/2∠DCB=∠DCE在△ABF和△CDE中∠ABF=∠CDEAB=CD∠BAF=∠DCE∴△ABF≌△CDE(ASA)∴AF=CE,∠AFB=∠CED∴∠AFE=180°-∠AFB =180°-∠CED=∠CEF∴AF∥=CE∴四边形AFCE为平行四边形