不难验证,选择适当的空间直角坐标系,正四面体的四个顶点的坐标就可以设为:(a,a,a),(a,-a,-a),(-a,a,-a),(-a,-a,a),其中a>0.利用距离公式得:正四面体的棱长为22(1/2)a.利用上述正四面体顶点坐标的巧妙设法,本文给出四面体中的几个有趣的定值,供参考. It is not difficult to verify that the coordinates of the four vertices of the regular tetrahedron can be selected as (a, a, a), (a, -a, -a), (- a, a, -a), (- a, -a, a), where a> 0. Using the distance formula is: Prism tetrahedral length is 22 (1/2) a. Using the above tetrahedron vertex coordinates clever way, This article gives a few interesting values ​​for tetrahedra for your reference.