摘要
本文首先给出四面体面积外法向量的概念,然后建立关于任意四面体四个侧面面积外法向量的一个恒等式,由此推出四面体的射影定理和余弦定理,并将结论推广至多面体中.
At first,this article shows the concept of the outer normal vector of the tetrahedral area and then sets up an identical equation about the outer nomal vector of the area of the four sides of any tetrahedrom.From this,it puts foward the projection theorem and cosine laws of the tetrahedrom,and extends the result of the polyhedrom
出处
《平顶山师专学报》
2003年第2期46-48,共3页
Journal of Pingdingshan Teachers College
关键词
四面体
面积外法向量
恒等式
tetrahedrom
the outer normal vector of the area
identical equation
