重点难点易混易错点剖析复习重点:三角形的概念,内角和与外角定理,三角形中线、角平分线、高等重要线段.三角形全等的识别.复习难点:钝角三角形高的画法,如何找到三角形全等的条件.易混易错点:解决问题有时需要作出一些辅助线,比如三角形中的高、中线、角平分线.判定全等三角形时需要注意对应关系,特别是选择条件证明全等时一定要注意至少要有一组“边”的条件.在用“SAS”证明三角形全等时,要 Key points Difficult to misuse Analysis of the wrong points Focus: the concept of the triangle, the angle and the outer angle of the theorem, the triangle center line, the bisector of the angle, the higher the important segments. Triangle congruent identification. Difficulties in review: obtuse triangle high painting, how to find Triangle congruent conditions. Easy to mix and error points: to solve the problem sometimes need to make some auxiliary lines, such as triangle in the high, middle, angle bisector. Judgment equivalent triangles need to pay attention to the corresponding relationship, in particular, the selection criteria that the total It must be noted that there must be at least one set of “edge” conditions. When using “SAS” to prove triangle congruent