苏州ae培训
(1)证明在平行四边形ABCD中,
∫AB∨CD,
∴∠BAF=∠CEF,∠ABF=∠ECF,
AB = CD,CE=CD,
∴AB=CE,
在△AFB和△EFC,
∠BAF=∠CEFAB=CE∠ABF=∠ECF,
∴△AFB≌△EFC.
(2)解法:ED = 2CD = 2AB,
∴EDAB=21,
∫AB∨CD,
∴DGGB=EDAB=21,
∫BD = 12,
∴DG=23BD=8cm,
答:DG的长度是8厘米。
∫AB∨CD,
∴∠BAF=∠CEF,∠ABF=∠ECF,
AB = CD,CE=CD,
∴AB=CE,
在△AFB和△EFC,
∠BAF=∠CEFAB=CE∠ABF=∠ECF,
∴△AFB≌△EFC.
(2)解法:ED = 2CD = 2AB,
∴EDAB=21,
∫AB∨CD,
∴DGGB=EDAB=21,
∫BD = 12,
∴DG=23BD=8cm,
答:DG的长度是8厘米。