已知控制点反推圆曲线的方法

Method of Referring Circular Curve Through Known Control Point

推导出了与直线或圆弧相切通过控制点的圆曲线半径和圆心点坐标的计算公式，介绍了该公式在ＭＥＣＡＤ软件中的应用情况．

 new formula for calculating the radius of circular curve being tangent with straight line or circular and passing through control point and the coordinate of its central point is advanced. The situation of the formula used in MECAD software is presented.