This definition of a circle briefly describes what a circle is with pictures showing the center, arc, sector, segment, radius, diameter and circumference of a circle.

The circle has been around long before the beginning of ancient history. A circle is the set of points in a plane that are equidistant from a **center point**. What this basically means is that if you measured from the center point to the edge of the circle, then you should get the same measurement no matter what direction you measure from.

The table below illustrates the unique characteristics of a circle that can be measured.

A picture of a circle showing the arc, sector and segment. |
A picture of a circle showing the radius. Find the radius. |

A picture of a circle showing the diameter. Find the diameter. |
A circle showing the circumference. Find the circumference. |