关于侧平线几个图学问题的探讨

主要探讨关于侧平线的空间几何问题， 如两条指向相同的侧平线平行与否的判定、交叉的一般线和侧平线重影点的可见性判别等问题， 使一些空间几何问题的求解， 比一般常用的方法更简便。

Discussion about Some Questions of the Profile Line

This paper discusses some questions about the profile line of space geometry,such as the judgement of the parallelism of the two profile lines with the same directions and the visibility about the skew lines and the reappeared points of profile lines, which make the solution of some questions in space geometry more easy than those commonly used.