如图:AB=AC,ED=EC,△ABC∽△EDC求证:AE//BC
如图:AB=AC,ED=EC,△ABC∽△EDC求证:AE//BC
如图,△ABC中,DE//BC,AD/BD=AE/EC,求证EC/AC=BD/AB
已知,如图,△ABC中,∠BAC=90.AD垂直BC,AE=EC,ED交AB的延长线于F,求证AB:AC=DF:FA
如图,△ABC中,AC=BC,AD是CB上的中线,点E在AB,AE=2BE.延长ED到F,使EF=EC,联结CF 求证C
已知:如图AE垂直AB,BC垂直AB,AE=AB,ED=AC,求证:ED垂直于AC
如图,已知△ABC中,AB-AC,F在AC上,在BA的延长线上截取AE=AF,求证ED垂直BC.
如图,D,E是△ABC的边BC上的两点,且BD=EC,求证:AB+AC=AD+AE
已知:如图,AD/AB=AE/BC求证:AD/AE=DB/EC和AB/DB=AC/EC
已知:如图6,△ABC中,∠A= 90°,AB = AC = BD ED⊥BC 求证:AE = DE =DC
如图,已知在△ABC中,AB=AC,点E在CA的延长线上,ED⊥BC于D.求证:AE=AF.
已知,如图,△ABC中,AB=AC,E在CA的延长线上,且ED⊥BC.求证:AE=AF
已知,如图,在△ABC中,AB=AC,E在CA的延长线上,且ED⊥BC.求证:AE=AF.