四面体即三棱维,它是最简单也是最基本的多面体.四面体在立体几何中的地位就象三角形在平面几何中的地位一样.由于四面体是三角形在空间的推广,因此,三角形的许多重要性质也都可以推广到四面体.比如:1°连接四面体对棱中点的线段交于一点,且互相平分.2°连接四面体任一顶点与它 The tetrahedron is the trigonal dimension, which is the simplest and most basic polyhedron. The position of the tetrahedron in the solid geometry is the same as the position of the triangle in the plane geometry. Since the tetrahedron is a generalization of the triangle in space, the triangle’s Many important properties can also be generalized to tetrahedrons. For example, 1° joins tetrahedrons to the point where the midpoints of the edges meet at a point, and they are evenly separated from each other. 2° connects any vertices of the tetrahedron with it.