One method of deriving this formula which originated with Archimedes involves viewing the circle as the limit of a sequence of regular polygons. O Circle diameter. The radius of a circle calculator uses the following area of a circle formula.
Visual on the figure below.
The Circle Formulas are expressed as Diameter of a Circle. Area of a Circle p 4 d2 Area of a Circle p 4 d 2. The Circle Formulas are expressed as Diameter of a Circle. Area of a circle radius.