C#

using System;

namespace Polymorph {
   public abstract class Shape {
      private int x;
      private int y;

      // constructor
      public Shape(int newx, int newy) {
         setX(newx);
         setY(newy);
      }

      // accessors for x & y coordinates
      public int getX() { return x; }
      public int getY() { return y; }
      public void setX(int newx) { x = newx; }
      public void setY(int newx) { y = newx; }

      // move the x & y coordinates
      public void moveTo(int newx, int newy) {
         setX(newx);
         setY(newy);
      }
      public void rMoveTo(int deltax, int deltay) {
         moveTo(deltax + getX(), deltay + getY());
      }

      // virtual routine - draw the shape
      public abstract void draw();
   }
}

using System;

namespace Polymorph {
   public class Rectangle: Shape {
      private int width;
      private int height;

      // constructor
      public Rectangle(int newx, int newy, int newwidth, int newheight): base(newx, newy) {
         setWidth(newwidth);
         setHeight(newheight);
      }

      // accessors for width & height
      public int getWidth() { return width; }
      public int getHeight() { return height; }
      public void setWidth(int newwidth) { width = newwidth; }
      public void setHeight(int newheight) { height = newheight; }

      // draw the rectangle
      public override void draw() {
         Console.WriteLine("Drawing a Rectangle at:({0},{1}), Width {2}, Height {3}",
            getX(), getY(), getWidth(), getHeight());
      }
   }
}

using System;

namespace Polymorph {
   public class Circle: Shape {
      private int radius;

      // constructor
      public Circle(int newx, int newy, int newradius): base(newx, newy) {
         setRadius(newradius);
      }

      // accessors for the radius
      public int getRadius() { return radius; }
      public void setRadius(int newradius) { radius = newradius; }

      // draw the circle
      public override void draw() {
         Console.WriteLine("Drawing a Circle at:({0},{1}), Radius {2}",
            getX(), getY(), getRadius());
      }
   }
}

using System;

namespace Polymorph {
   class Polymorph {
      static void Main(string[] args) {
         Shape[] scribble = new Shape[2];
         Rectangle rect;

         // create some shape instances
         scribble[0] = new Rectangle(10, 20, 5, 6);
         scribble[1] = new Circle(15, 25, 8);

         // iterate through the list and handle shapes polymorphically
         for (int i = 0; i < scribble.Length; i++) {
            scribble[i].draw();
            scribble[i].rMoveTo(100, 100);
            scribble[i].draw();
         }

         // call a rectangle specific function
         rect = new Rectangle(0, 0, 15, 15);
         rect.setWidth(30);
         rect.draw();
      }
   }
}

Drawing a Rectangle at:(10,20), Width 5, Height 6
Drawing a Rectangle at:(110,120), Width 5, Height 6
Drawing a Circle at:(15,25), Radius 8
Drawing a Circle at:(115,125), Radius 8
Drawing a Rectangle at:(0,0), Width 30, Height 15