全等三角形及其应用因为涉及两个三角形的位置关系和数量关系,因此,解题时常会出错.就常见的错误,分类辨析如下.u0017“一、局部代替整体例1如图1,已知点A,E,F,D在同一直线上,且AE=DF,CE=BF,CE∥BF.试说明AB=CD.图1错解在△ABF和△DCE中,BF=CE,AE=DF.又CE∥BF,所以∠1=∠2.所以△ABF Congruent triangles and their applications because of the relationship between the location and quantity of the two triangles, therefore, the problem will often be wrong. For common errors, the classification is as follows.u0017”I. Partial substitution of the overall example 1 as shown in Figure 1, Known points A, E, F, D on the same line, and AE = DF, CE = BF, CE ∥ BF. Test description AB = CD. Figure 1 The wrong solution in △ ABF and △ DCE, BF = CE, AE = DF. And CE ∥ BF, so ∠ 1 = ∠ 2. So △ ABF