摘要
在机械制图工作中 ,有时需要由投影求出直线的实长。而采用直角三角形法、换面法和旋转法求出一般位置直线的实长对于提高工作效率和数据的准确度有着重要的意义。
It proved necessary to assess the substantial length of straight line in the work of chart making.The essay recommends three ways of assessing the substantial length of straight line in average positions,which turned out significance in improving efficiency and precision of data.
关键词
实长
直角三角形法
换面法
旋转法
机械制图
Substantial length
Right triangle
Superficial Changing
Rotation
