The outlining curve of an isometric polygon is one of the un-rounded curves, it is difficult to measure its parameters and calculate the errors. 摘要等距型面轮廓曲线为非圆曲线的一种，对其参数的测量和误差的计算比较困难，目前尚没有统一的评价标准。
There are many methods to measure the circular curved line in circuitry construction survey.Angle offset method and tangent offset method are usually used. 摘要在线路施工测量中，圆曲线测设方法有很多，通常采用偏角法或切线支距法。
