Definition of Center of a Circle, Radius of a Circle and Diameter of a Circle
The origin or center of a circle is the center point in a circle from which all the distances to the points on the circle are equal.
The radius of a circle is a straight line joining the origin or center of a circle to any point on the circle.
The diameter of a circle is a straight line joining any two points on the circle such that it passes through the center or origin of a circle.
Radius of a circle is half of its diameter.
That is,
`Radius=frac{Diameter}2`
Or conversely, diameter of a circle is double of its radius.
`Diameter=2times Radius`