直角投影定理逆定理的研究与推论  

Investigation and Supplement Basedon of Rectangular Projection Theorem Converse Theorem

作　　者：董金华[1] 程军[2] 闫利文[3] 

机构地区：[1]河北科技大学机械电子工程学院,河北石家庄050054 [2]上海工会管理干部学院,上海200054 [3]常熟高等专科学校机电系,江苏常熟215500

出　　处：《河北科技大学学报》2003年第1期51-53,共3页Journal of Hebei University of Science and Technology

摘　　要：通过对《画法几何学》中直角投影定理的逆定理的研究,得出:“若垂直相交的两直线在某一投影面上投影成直角,则该两直线至少有一条直线平行于该投影面”的推论。此推论使得直角投影定理自身更趋于完整,同时,对垂直相交两直线的判断和作图也有一定帮助。This paper investigates the converse theorem of rectangular projection theorem in descriptive geometry,and furthermore supplements and confirms another converse theorem,'If the projection of two lines intersecting vertically fo'rms a rectangle on a certain projecting plane,at least one line of the two lines is parallel to the projecting plane. ' This supplement to the theorem perfects the rectangular protection theorem,and helps judge two lines intersecting vertically and draw graphs.

关 键 词：直角投影定理 逆定理 垂直 平行 

分 类 号：TH126.2[机械工程—机械设计及理论]