证明:∵AB=AC∴△ABC是等腰三唯卖角形∴∠ABC=∠谈镇ACB∵含山粗DG平行AC∴∠GDF=∠AED∵∠DFG=∠CFE(对顶角相等)∠ACB=∠AED+∠CFE因为∠ACB=∠ABC∴∠ABC=∠AED+∠CFE∵∠DGB=∠GDF+∠DFG∴∠ABC=∠DGB所以△DGB是等腰三角形∴DB=DG∵DB=CE∴DG=EC(2有(1)易证△DGF全等三角形CFE(AAS)∴FD=FE