我们知道,平面上的正多边形,可以有正三角形、正方形、正五边形、正六边形等等.对于任意一个正整数n,都有正n边形存在.平面上的多边形,类比到空间,就是多面体——由若干个平面多边形围成的封闭的空间图形.围成多面体的各个多边形叫多面体的面,两个面的公共边叫多面体的棱,棱和棱的公共点叫多面体的顶点.把多面体的任一面伸展成平面,如果其余的面都位于这个平面的同一侧,这样 We know that regular polygons on a plane can have regular triangles, squares, regular pentagons, regular hexagons, etc. For any positive integer n, there is a positive n-sided polygon. The polygon on the plane, analogy to space Is a polyhedron - a closed space graph surrounded by a number of planar polygons. Polygons enclosed in a polyhedron are called polyhedral faces. The common edges of two faces are called polyhedral edges. The common point of edges and edges is the vertex of the polyhedron. Stretch any face of a polyhedron into a plane if the rest of the faces are on the same side of the plane.