如图,在三角形ABC中,AB=AC,在BA的延长线上取一点E,在AC上取一点F,使AE=AF.求证:EF垂直BC.

如图,在△ABC中,AB=AC,在BA的延长线上取一点E,在AC上取一点F,使AE＝AF.求证：EF⊥BC 如图,在三角形ABC中,AB=AC,E是BA延长线上一点,DE垂直BC于D,交AC于F.求证:AE=AF 已知三角形ABC中AB=AC,F在AC上,在BA延长线上取AE=AF,求证:EF垂直BC 如图,三角形ABC中,AB=AC,在BA的延长线上取AE=AF,求证EF垂直BC 如图所示,已知三角形ABC中,AB＝AC,F在AC上,在BA的延长得线上取AE＝AF,求证EF垂直BC 如图所示,已知三角形ABC中,AB=AC,F在AC上,在BA的延长线上取AE=AF,求证：EF⊥BC. 如图,已知三角形ABC中,AB=AC,在BA延长线上取AE=AF,求证：EF垂直于BC 如图,已知三角形ABC中,AB=AC,F在AC上,在BA的延长线上截取AE=AF,求证BD垂直于BC 在△ABC中,AB=AC,在AC上取一点E,在BA的延长线上取一点D,使AD=AE,连接BE并延长BC于F,求证：DF⊥ 在三角形ABC中 AB=AC E在CA的延长线上 F在AB上 且AE=AF 求证EF垂直BC 如图所示,已知△ABC中,AB=AC,F在AC上,在BA延长线上取AE=AF,求证:EF⊥BC 如图,在△ABC中,AB=AC,在AB上取一点D,在CA的延长线上取一点E,使AE=AD,连接ED并延长交BC于F.求证