The concept of the chord in a school course of geometry associated with the concept okruzhnost.Okruzhnostyu called a plane figure composed of all points of the plane equidistant from a given plane.
Circle radius is the distance from the center to any point lying on ney.Hodoy called a segment connecting any two points on the circle.
The longest chord passes through the center of the circle, while it is called in diameter, and is denoted by d. The length of this chord is
d = 2 * R, where R - radius of the circle.
For the length of any chord you must enter additional concept.
The angle with vertex at the center of the circle is called the central angle of the circle.
If we know the degree measure of central angle ??, the length of the chord on which it is based is calculated according to the formulas
h = 2 * R * sin (?? / 2)
h = R * v (2 * (1 - cos ??))
h = 2 * R * cos ??, where ?? = (P - ??) / 2, P - P number