本文约定,如果三角形的三个顶点分别位于另一个三角形的三条边(不含端点)上,则称前者为后者的内接三角形.作为原三角形的衍生三角形,内接三角形具有“模型”意义,值得研究.举例来说,以三角形三条中位线为边的三角形(称为中位三角形),是原三角形的内接三角形.这两个三角形显然相似,并且内接三角形的顶点分别位于原三角形对应顶点的对边上,即二者的对应顶点不共边.顺便说明,下文凡涉及“三角形 In this paper, if the three vertices of the triangle are located on the three sides of the other triangle (excluding the end point), then the former is the latter’s inscribed triangle. As the original triangle derived triangle, the inscribed triangle has For example, a triangle centered on the middle three triangles of the triangle, called the median triangle, is the inscribed triangle of the original triangle, which is apparently similar and the vertices of the inscribed triangle, respectively Is located on the opposite side of the corresponding vertex of the original triangle, that is, the corresponding vertices of the two are not common. By the way, the following paragraphs refer to the ”triangle