圆面积公式
圆面积公式-
圆面积公式与圆周率究竟是怎样推求的
How to Calculate the Area of Circle and Ratio of the Circumference of to Its Diameter ITO formula of a function of
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统计典型区域中毛细管个数，参照圆面积公式得到纱线中毛细管当量半径。
According to the area of capillaries , the number of capillary and the formula of circle , the equivalent radius of the five kinds of the yarns was gotten .