In this paper, an area formula of polygon of inscribed or circumscribed ellipse is presented and the condition that the area reaches maximum value or minimum value is discussed.
提出了椭园内接或外切多边形面积公式，并讨论了其面积达到最大值与最小值的条件。
2
To enhance the precision of ellipse gyre surface, gives the scheme of the ellipse gyre surface with 2-axis NC machining before polishing and its formula of the minimum survature radius.