// declaration of a class of Circle objects

class Circle
{
public:
   void SetCenter(double x, double y);	// a "setter" function
   void SetRadius(double r);		// a "setter" function

   void Draw() const;		// will not change object
   double GetArea() const;	// a "getter" -- type of accessor

private:
   double radius;
   double center_x;
   double center_y;
};