On the basis of analytic geometry, the projection curve types of intersection lines of cone and cylikder, cone and cone on V plane is hyperbola and cone and sphere is parabola.

• 中专制图教科书中 ,对圆柱与圆锥轴线垂直相交时 ,相贯线投影作图 ,大都采用先找特殊点 ,再用辅助平面法找一般点 ,最后判断点的可见性并描点连线的方法。