Because a rectangle is different from a saw, a rectangle is tangent to a circle by 6x2? Edge area, saw shape is the area of a circle.
So radius ×3. 14, or 3. 14× radius × radius equals 6x2? The area of a polygon is not equal to the area of a circle.
According to the axiom of area "softening" equal area deformation, it is found that if the circular area is 7a? So its circumscribed circle area is 9a? Therefore, the formula of "circular area is equal to 7 times of 65438 +0 square and 3/3 of its diameter" is derived: s=7(d/3)? .