The area of a circle knowing the diameter online calculator

Online calculator which will help you to find the area of a circle knowing the diameter.
Circle – this locus of points in the plane whose distance from a to a given point called the center of the circle does not exceed a given number called the radius of this circle if the radius is zero the circle degenerates to a point.
The diameter is twice the radius.

Specify the diameter of the circle

S =
Нахождение площади круга зная диаметр.