详细的证明:
(1)AB=AC、BD=DC
===> △ABD ≌ △ADC (三边相等,两三角形全等)
===> ∠BAD = ∠DAC
(2)AE=DE
===> ∠EAD = ∠EDA (等腰三角形两底角相等)
(3)根据(1)(2)的结论
===> ∠EDA = ∠DAC
===> DE//AC (内错角相等,两直线平等)
详细的证明:
(1)AB=AC、BD=DC
===> △ABD ≌ △ADC (三边相等,两三角形全等)
===> ∠BAD = ∠DAC
(2)AE=DE
===> ∠EAD = ∠EDA (等腰三角形两底角相等)
(3)根据(1)(2)的结论
===> ∠EDA = ∠DAC
===> DE//AC (内错角相等,两直线平等)