A PolygonObject which is round and defined by its radius, which is the distance from its center. Also, the  diameter is twice the radius, and the area=2*pi*r^2. Its center is usually defined as (x,y) in CartesianCoordinates.

AntiComment:
 //int radius
 //PointObject center
 //int Area()
 //int Diameter()
 //void draw(string color,int r,int x,int y)
 //{
 //   //more detailed code
 //}
 //link to result of WikiCodeRunner
 //

''What's the context for this page?'' AntiComment, I think.