一、多边形的知识点1.n边形有n个顶点、n条边、n个内角.2.在多边形的知识中,难点是对角线.从一个顶点可以引(n-3)条对角线,则从n个顶点可引n(n-3)条.但是,从“这一点引向另一点”与“由另一点引向这一点”重复,所以,n边形共有n(n-3)/2条对角线.二、多边形的内角和定理多边形的内角和等于(n-2)·180°(n为多边形的边数).我们可以看到,内角和随着边数的变化而变化.边数每增加1,内角和就增加180°. First, the knowledge of polygons 1.n polygons have n vertices, n edges, n interior angles .2. In polygon knowledge, the difficulty is diagonal. From a vertex can lead (n-3) to (N-3) bars from n vertices, however, it is repeated from “this point to another point” and “from this point to another point”, so that the n-polygon There are n (n-3) / 2 diagonal lines. 2. Polygon’s interior angles and theorems The polygon’s interior angle is equal to (n-2) · 180 ° (n is the number of sides of the polygon.) We can see that the interior angles As the number of edges changes, the number of sides increases by 180 ° for every 1 increment.