There are inclucded angels between the surfaces trace lines of common place plane and projecting shafts, and at the sametime, there are inclinations between common place plane and projecting surfaces.

• 研究了斜井素描过程中 ,面理在硐顶的迹线的描绘方法 ,对倾向、倾角和倾伏向、倾伏角、侧伏向、侧伏角、侧余角的关系作了较深入的研究。