I am not sure the origins of this site, appears to be US but the focus is SI. They have an area calculator and it's in cm. Many of the sample problems are in meters.
http://www.mathsisfun.com/geometry/circle-area.html Howard Ressel Project Design Engineer NYSDOT 1530 Jefferson Road Rochester, NY 14623 585 272-3372 43,560 square feet in an acre 5280 feet in a mile 16 ounces in a pound 128 ounces in a gallon 23 confused kids in a class What could be simpler?
