“面积法”是平面几何中解决问题的一种重要方法,平面几何中基本方法能解决的问题绝大部分都可用“面积法”来解决.笔者用“面积法”推导三角形的角平分线定理时联想到,去除“角平分线”这个条件时,三角形中的边的比例关系是否存在?探究得两个三角形中的边角关系结论,并用它来尝试解决了平面几何题. The “area method” is an important method of solving problems in plane geometry. Most of the problems that can be solved by the basic methods in plane geometry can be solved by the “area method”. The author uses the “area method” to derive The angle bisector theorem of triangles is associated with whether or not the ratio of edges in triangles exists when the condition of “angle bisectors” is removed. The result of the relationship between the corners of two triangles is explored and used to solve the problem. Plane geometry problem.