Circle is called the geometrical figure on the plane which consists of all points of this plane which are at identical distance from the set point. The set point at the same time is called the center of a circle, and distance at which points of a circle are from its center – circle radius. The area of the plane limited by a circle is called circle. There are several methods of calculation of diameter of a circle, the choice concrete envy from the available initial data.
Instruction
1. In the simplest case if to construct R radius circle, then its diameter ravend = 2 * the radius of a circle will not be known to REsli, but its length is known, then diameter can be calculated on length formula okruzhnostid = L/P where L – circle length, P – number P. Also diameter of a circle can be calculated, knowing the area of a circle it ogranichennoyd = 2 * v(S/П) where S is the area of a circle, P – number P.
2. Radius of a circle can be found in special cases if it is described or inscribed in a triangle. If the circle is inscribed in a triangle, then its radius is on formuler = S/p where S is the area of a triangle, p = (a + b + c)/2 – poluperimetr a triangle.
3. For a circle, circumscribed about a triangle, the formula of radius has vidr = (a * b * c)/4 * S where S is the area of a triangle.