证明:(1)∵EF∥BD∴DF/AF=BE/AE∵BE=DF∴AE=AF∴∠E=∠F(2)∵AD=AF-DF,AB=AE-BEAF=AE,DF=BE∴AD=AB∴平行四边形ABCD是菱形.
你没写错BE=BF?