(4)全等三角形的应用三角形,是平面几何中最基础的也是最重要的图形.三角形全等则是两个图形之间最重要的也是最有用的关系.两个三角形一旦全等,那么它们的一切对应部分就相等.从这个基本点出发,我们可以利用三角形全等求三角形的元素(角、边、高线、中线、角平分线、面积等)或解决很多证明问题. (4) The application triangle of the equal triangle is the most basic and most important figure in the plane geometry. The triangle equal is the most important and most useful relationship between the two figures. Once the two triangles are equal, then All of their corresponding parts are equal. Starting from this basic point, we can use triangles to find the triangle elements (corners, edges, highs, midlines, angle bisectors, areas, etc.) or solve many problems.