Area and Circumference of a circle

What is the Circumference?
The distance around a circle.

All lines in a circle:
Circumference - The distance around a circle.
Diameter - The distance across a circle through the center.
Radius - The distance from the center of a circle to any point on the circle.

How to find the area of a circle:
Just follow this equation:
external image areaformula.JPG
R stands for radius

Citations: http://www.mathgoodies.com/lessons/vol2/circumference.html