The area of geometric figures is an important characteristic of them, which is used both in science and in technology.
A circle is a set of points equidistantFrom the same point of the plane, called the center of the circle. The distance from any point of the circle to the center is called the radius of the circle. A circle is a part of a plane bounded by a circle.
The area of the circle S can be found by the formula: S = Π- * R²-, where R is the radius of the circle, and Π- is the number of pi.
If you know the diameter, not the radius of the circle, then remember that D = 2R. Then it is easy to see that the area of the circle can be calculated in this way: S = Π- * R²- = Π- * (D / 2) ²- = Π- * D²- / 4