Circle is the most important geometrical figure. A circle is defined as the locus of a point that is equidistant from a fixed point. In other words, circle is the set of all points that lie at same distance from a point.

The diagram of circle is shown below:

There are many terminologies that are associated with circle. Few important ones are as follows:

**Center :**The fixed point inside the circle, from where each point on circle is at equal distance, is known as center.**O**" in above figure.**Radius :**The distance from center to any point lying on the circle is called radius of the circle. Radius for a circle is fixed. It is generally denoted by "**r**".**Diameter :**The diameter of a circle is line passing through center and meeting in circle on both sides. Diameter is shown in the above figure.**Circumference :**Circumference is referred to the boundary of the circle.

2) Radius of a Circle:

4) Area of a Circle:

Related Calculators | |

Circle Calculator | Circumference a Circle |

Area Calculator Circle | Chord of a Circle Calculator |