题目应该输入错误了吧?应该是AB:AD=3:5在在平行四边形ABCD中,AB=CD,AD=BC.AD平行BC,则角DAE=角AEB;又因为AE平分角BAD,则角BAE=角DAE,所以角BAE=角AEB,则AB=BE.设AB=3k,AD=5k.则CE=BC-BE=AD-AB=2k=4,所以k=2.则AB=CD=...