摘要:已知三角形的任意两个内角与两角所夹边长即可计算出该三角形的面积，本文将该类三角形面积公式推广至n维单形，给出了关于n维单形的二面角、棱面角、n-1维子单形、n-2维子单形之间的关系。

Abstract:The area of a triangle can be calculated by known any two internal angles of the triangle and the side length between the two angles. In this paper, this kind of area formula for the triangle is extended to n-simplex, the relations among the dihedral angle, the line plane angle, the n-1-sub-simplexand the n-2-sub-simplex for the n-simplex are given.