第一部分知识要点本单元的主要内容可以分为四大部分：一是三角形有关元素的概念和性质；二是全等三角形的概念、性质、判定及应用；三是特殊三角形的概念、性质和判定；四是轴对称和轴对称图形的概念、性质和基本作图．本单元的重点是全等三角形的概念、性质、判定和应用．一 The first part of the knowledge points The main content of this module can be divided into four parts: First, the concept and nature of the triangular related elements; Second, the concept, nature, determination and application of congruent triangles; Third, the concept, nature and judgment of special triangles Fourth, the concept, nature and basic drawing of axisymmetric and axisymmetric graphs. The focus of this module is the concept, nature, determination and application of congruent triangles. one