use Inline::Java; # grin ;-)

      Shape[] shapes = new Shape[100];
      shapes[0] = new Rectange(45,27);
      shapes[1] = new Circle(10);
      shapes[2] = new Ellipse(25,13);
      shapes[3] = new Quadrilateral(15,20,50,14);
            ...

      double area = 0;
      for (int i=0; i < shapes.length; i++)
           area += shapes[i].computeArea();