A center chord in a circle is the diameter of that circle. Therefore a center chord of a circle is different from other chords that touch two points on the circle but not in the center of the circle. A diameter of a circle is the chord that runs the length of the center of the circle touching two points at the edge of the circle. A diameter is twice the radius of the circle. So if the diameter of the circle is 12cm then the radius of the circle is 6cm
