ABCDEFABACBCDE//BCADA5:8B.3:8C.3:5D.2:5相似三角形典型例题、专题DB=3:5EF//ABCFCB甘FC2L1〃L2,AF:FB=2:3,BC:CD=2:1,AEECA.5:2B.4:1C.2:1D.3:2I.ft/>3DC//EF//GH//AB,AB=12,CD=6,DE:EG:GA=3:4:5.EFGHGAE=2EC,AH=2HD,BG=2GC,BF=2FD,EF,GHEF//J)5PABCMNBPCPACABDEAD/DC+AE/EB=1.6)A.B.C.D.ABC812cm12cm2cmA4B.5C.6D.7t2t34949.SABC二.10ABCBACB',EFAB=AC=8BC=10B'FCABCBF11)ABCDBCDEBCABEAD二ACECAD12ABCDBCCDAEAFBDAGHCEGHFA.1B.2C.3D.413ABCAB=AC=m,ABC=72,BBiABCACBrBrB1B2//BCABB2B2B3AB2B1ACB3B3B3B4〃BCABB4B9B10m14ABCDEADCEBAEBACDMBMADAFN二DME15ABCADBACADADEBCFFD2=FBFC16ABCA=90DABEACFG17HABCADBHCHACABEF.EDH二FDH.18ABC二BAD=90AB=16ACBDEEFABFOABAD+BC.ABCDFE+EO=8.19ABCDFDCBFACEAD/AB=1/2.CEFSiAEBS2S/S2A1/16B.1/5C.1/4D.1/2520ABCDA=BCD=90BDBDADEFACDCFDAC21ABCBAC=90ADBC,DPADBPACEEF22ADAEABCDE2AB=3ACBDDCCEBCBC
