Radius
From the Simple English Wikipedia, the free encyclopedia that anyone can change
In geometry, the radius of a circle or sphere is the shortest connection between the center and the boundary. It is half of the diameter.
The relationship between the radius
and the circumference
of a circle is 
The area
of a circle of radius
is 
[change] See also
[change] Other websites
- Definition and properties of the radius of a circle with interactive applet

