题目内容
如图所示,在平行四边形ABCD中,E、F是对角线BD上的两点,且BE=DF.
求证:(1)AE=CF;(2)AE∥CF.

求证:(1)AE=CF;(2)AE∥CF.

证明:(1)∵四边形ABCD是平行四边形,
∴AB=CD,AB∥DC.
∴∠ABE=∠CDF.
又BE=DF,
∴△ABE≌△CDF.
∴AE=CF.
(2)∵△ABE≌△CDF,
∴∠AEB=∠CFD.
∴∠AEF∠CFE.
∴AE∥CF.
∴AB=CD,AB∥DC.
∴∠ABE=∠CDF.
又BE=DF,
∴△ABE≌△CDF.
∴AE=CF.
(2)∵△ABE≌△CDF,
∴∠AEB=∠CFD.
∴∠AEF∠CFE.
∴AE∥CF.

练习册系列答案
相关题目