已知AE⊥AD,AF⊥AB,AE=AD=BC,AD‖BC,求证:⑴AC=EF⑵AC⊥EF如题

如图,已知AD//BC,AD=BC,AE⊥AD,AF⊥AB,AE=AD,AB=AF.求证：AC=EF. 如图,已知AE⊥AD,AF⊥AB,AB//CD,AE=CD,AE=AD,AF=CD,求证AC=EF 如图,已知AE⊥AD,AF⊥AB,AF=AB,AE=AD=BC,AD‖BC,求证AC⊥EF 已知AD是△ABC的中线AE⊥AB,AF⊥AC且AE=AB,AF=AC连接EF求证AD=1/2EF 已知AD是△ABC的中线AE⊥AB,AF⊥AC且AE=AB,AF=AC连接EF求证AD=1/2EF 如图,已知AE⊥AD,AF⊥AB,AB∥CD,AF=CD,AE=AD,求证：AC垂直EF. 如图,AD∥BC,AD=BC,AE⊥AD,AF⊥AB,且AE=AD,AF=AB,求证：AC=EF. 已知AE⊥AD,AF⊥AB,AE=AD=BC,AD‖BC,求证:⑴AC=EF⑵AC⊥EF如题 如图,AB‖CD,AD‖BC,AE⊥AB,AF⊥AD,AE=AB,AF=AD,试说明AC=EF 如图9,AD//BC,AE⊥AD且AE=AD,AF⊥AB且AF=AB.则AC与EF是否相等?为什么? 如图,已知AE⊥AD,AF⊥AB,AF=AB,AE=AD=BC,AD∥BC,求证：（1）AC=EF（2）AC⊥EF不用平行四边形 如图,已知AE⊥AD,AF⊥AB,AF=AB,AE=AD=BC,AD∥BC,猜想线段AC,EF的关系,并证明你 全等三角形证明题(初二上册)如图,已知AD为△ABC中线,AB⊥AE,AB=AE;AC⊥AF,AC=AF,求证：EF=2AD(注:未说AB=AC) 已知,如图,AB=AD,CB⊥AB,CD⊥AD,E,F分别是BC,DC的中点求证AE=AF急! 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,已知：AB=AE,AC=AD,AC⊥AD,AB⊥AE.求证：ED⊥BC. 如图所示,已知AB⊥AC,AD⊥AE,AB=AC,AD=AE,求证：BE=DC