## Circle definition

A circle is a set of points in a plane whose distance from a fixed point (the centre of a circle) is less than or equal to a fixed positive number (called a radius).

## Circle calculators

Use calculators to make circle calculations of radius, diameter, circumference (perimeter), area (circular area), chord height (sagitta, arc height), arc length, circle segment, circle sector angle.

## Circle parts

- Circle center is the point within a circle that is in same distance from all other points on the circle.
- Circle radius is any of the line segments from its center to its perimeter
- Circle diameter is any straight line segment that passes through the center of the circle and whose endpoints lie on the circle. It can also be defined as the longest chord of the circle.