绝缘电阻表以前是按标度尺弧长定义的弧长误差，现行国家标准规定以指示值的百分数表示。
Formerly the arc length error for the insulation resistance instrument is defined by scale arc length. At present national standard determines that the percentage of indicated value expresses it.
用尺规将一个任意角或弧绝对准确三等分是不可能的。
It is impossible to divide a given common Angle or arc (instead of the particular angles or arcs) into three equal parts by using a rule and compasses.
旋 转尺能当作一个简易圆规使用，能根据需要画弧、画圆，同时能 确定两物体的位置与方向。
The rotary ruler can be used as simple compasses, can be used to draw arcs and circles according to demands, and can be used to define positions and directions of two articles simultaneously.
应用推荐