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

在几何中一直以弓高弦长等法整形圆弧半径值。

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.

为了降低误差,提出了对整形圆弧直径的法。