Because "the area of a circle is 7/9 of the area of its circumscribed circle", there is no need to use any software to derive the positive 6x2 from the area of the circle. The area formula of polygon πR? .

First of all, we should know: draw the largest circle in a square. How much does this circle occupy in the square area?

Because the size of the area is determined by the number of points. A unit is a square point. The inscribed circle of a square point is a point. The diameter of a point is called the point diameter. When the field diameter is 1, which is 3/3 of the side length of a square, the square has 9 points, so the area of the square is equal to the square of the diameter of 9 points. Because the maximum inscribed circle of a square has seven points, the maximum inscribed circle area of a square (according to the axiom of softening equal product deformation) is equal to the square of the diameter of seven points.