图纸上的几何图形是在绘图板上用绘图仪器画成的.很多图形是借助一个、两个甚至几个辅助圆找规矩后画出来的。在施工现场要将这些图形放成实样进行施工,如果用绘图板上的方法就十分困难,画很多的圆不但麻烦,而且,也没有那么宽敞的场地。这里介绍几种简捷实用的画法。一、垂线的画法一般情况,用方尺便可画出AB The geometry on the drawings is drawn on the drawing board with a drawing instrument. Many of the drawings are drawn using one, two, or even several auxiliary circles. In the construction site, these figures should be put into actual construction. If the method on the drawing board is very difficult, drawing a lot of circles is not only troublesome, but also it is not so spacious. Here are a few simple and practical painting techniques. First, the general situation of vertical line drawing, can be drawn with a square rule AB