摘要:
用Cayley-Menger行列式证明：当四面体满足“对棱相等、或对棱的平方和相等”时，存在体积勾股定理：“该四面体的体积的平方等于所围的四个面外凸的直角四面体体积的平方和”，其公式为：
(标注见：图1)。
Abstract:
Cayley-Menger determinant is used. It is proved that the tetrahedron satisfies the condition that the opposite side is equal or that the opposite side is the sum of squares identically equal . volume Pythagorean theorem has been found：The square of the volume of a tetrahedron is the sum of squares the volume of four convex right-angled tetrahedrons. The formula is:
. (The label is shown in Figure 1).