Class Poly (The Application)
public class Poly {
    private Polyhedron p1, p2, p3;
    public static void main(String [] argv) {
        Poly thisApp = new Poly();
        thisApp.p1 = new Cube(5);
        thisApp.p2 = new Tetrahedron(10, 8, 7);
        thisApp.p3 = new RectangularParallelopiped(2, 3, 4);
        thisApp.p1.describe();
        thisApp.p2.describe();
        thisApp.p3.describe();
    }
}