public class Dyad extends Ball  
BEGIN   

   public Dyad() // constructor
   BEGIN
      Ball() // call constructor method of super class
   END
   
   public void draw() // over rides draw method of super class
   BEGIN
      integer radius = SuperClass.getRadius()
      integer x = SuperClass.getX()
      integer y = SuperClass.getY()
      set colour for drawing to color
      drawFilledOval in bounding rectangle, 
		top left (x, y), bottom right (x + 2*radius, y + 2*radius)
      drawFilledOval in bounding rectangle, 
		top left (x+radius, y), bottom right (x + 3*radius, y + 2*radius)
   END
    
END  // end class Dyad