Geometry/Circles/Radii, Chords and Diameters

A circle is a set of all points in a plane that are equidistant from a single point; that single point is called the centre of the circle and the distance between any point on circle and the centre is called radius of the circle. http://en.wikipedia.org/upload/d/dd/Circle-2.png Chord a chord is an internal segment of a circle that has both of its endpoints on the circumference of the circle. the diameter of a circle is the largest chord possible Secant a secant of a circle is any line that intersects a circle in two places. a secant contains any chord of the circle Tangent a tangent to a circle is a line that intersects a circle in exactly one point, called the point of tangency. at the point of tangency the tangent line and the radius of the circle are perpendicular