Circle Geometry Widget

Learn about Circle Geometry

A circle is a shape containing a set of points that are all the same distance from its center. A circle has some important dimensions: the radius, the diameter and the circumference. It also has an area, which is the amount of space contained by a circle.

Interactive Widget

This widget allows you to find the radius, diameter, circumference and area of a circle.

Draw a circle by:
  • Clicking on the canvas, or
  • Entering any dimension.

Radius:


Diameter:
= 2 × radius


Circumference:
= 2 × π × radius


Area:
= π × radius2
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See Also

What is a circle? What is the radius? What is the diameter? What is the circumference? Finding the area of a circle