We will divide it into 3 cases. The area of a regular polygon is half its perimeter multiplied by the distance from its center to its sides and the corresponding formulathat the area is half the perimeter times the radiusnamely A 1 2 2pr r holds in the limit for a circle. The area is measured as the half region of the rectangle.
Alternatively the formula to calculate the area of a rectangle is derived by dividing the shape into two equal size right triangles.
Since the circumference is equal to 2pr the base has to be pr. Brahmaguptas formula provides the area A of a cyclic quadrilateral ie a simple quadrilateral that is inscribed in a circle with sides of length a b c and d as where s is the semiperimeter Note. As far as I know there are two options. Thus the area of ABCD will be.