如图,AB=AC,AE=AF,AF⊥EC于E,AF⊥FB于F.求证∠1=∠2.

如图,AB=AC,AE=AF,AF⊥EC于E,AF⊥FB于F.求证∠1=∠2. 已知：如图,AB=AC,AE=AF,AE⊥EC,AF⊥BF,则∠1=∠2吗?为什么? 已知:如图,AB=AC,AE=AF,AE⊥EC,AF⊥BF,则∠1=∠2吗?为什么? 如图所示,已知ae⊥ab,af⊥ac,ae=ab,af=ac.求证ec⊥bf 如图,AB=AC,AE=AF,AE垂直于EC于点E,AF垂直于FB与F.求证:角1=角2 已知：如图,EF‖BC,AE²=AD·AB.求证：DF‖EC.【EF‖BC,平行线分直线,成比例AE/AB=AF/AC,AE²=AD·AB,AD/AE=AE/AB=AF/ACDF‖EC】这是解法、可是为什么AD/AE=AE/AB=AF/AC,DF就平行EC、要理由 已知：如图,EF‖BC,AE²=AD·AB.求证：DF‖EC.【EF‖BC,平行线分直线,成比例AE/AB=AF/AC,AE²=AD·AB,AD/AE=AE/AB=AF/ACDF‖EC】这是解法、可是为什么AD/AE=AE/AB=AF/AC,DF就平行EC、要理由 如图所示,已知AE⊥AB,AF⊥AC,AE=AB,AF=AC.求证：（1）EC=BF；（2）EC⊥BF. 已知AE⊥AB,AF⊥AC,AE=AB,AF=AC.试证明:(1)EC=BF;(2)EC⊥BF 如图所示,已知AE⊥AB,AF⊥AC,AE=AB,AF=AC.求证①EC=BF②EC⊥BF. 如图所示,已知AE⊥AB,AF⊥AC,AE=AB,AF=AC.求证：（1）EC=BF；（2）EC⊥BF 已知AE⊥AB,AF⊥AC,AE=AB,AF=AC.试证明:(1)EC=BF;(2)EC⊥BF 如图,已知AE=AB,AF=AC,EC=BF,求证:∠BAE=∠CAF 如图所示,已知AE垂直AB,AF垂直AC,AE=AB,AF=AC,求证.EC垂直BF 已知:如图,AB=AC,AE=AF,AE⊥EC,AF⊥BF,则∠1=∠2吗七年级下学期暑假作业上63页的第2小题, 如图所示,已知AE⊥AB,AF⊥AC,AF=AC,求证：（1）EC=BF（2）EC⊥BF 如图,已知AE⊥AD,AF⊥AB,AB//CD,AE=CD,AE=AD,AF=CD,求证AC=EF 已知:如图AB=CD AE=FD BF=EC 求证AF=ED