《三角形》一章是同学们学习几何证明的基础.在学习过程中,有些同学常常对几何证明题辅助线的添加方法显得束手无策,下面笔者就谈一谈三角形中常见辅助线的作法.一、倍长中线法. 遇到三角形的中线问题,常延长中线,使延长线段与原中线相等,构 The “Triangle” chapter is the basis for the students to learn the geometric proof. During the course of the study, some students often find it difficult to add methods to the auxiliary lines of the geometrical proofs. The following writer talks about the common auxiliary lines in triangles. Double-length midline method. When you encounter a triangle midline problem, you often extend the midline so that the extension line is equal to the original midline.