People used to measure the radius of nonplastic circular by the length of bowstrings in the geometric calculation .

在几何量量中一直以长等方法量非整形径值。

In order to reduce the error in the calculation, this article raises a measure method to the radius of nonplastic circular arc which basis on the principle of geometry.

为了降低量误差,提出了对非整形直径量的方法。