import java.util.ArrayList;
public class Driver
{
    public static void main(String[] args)
    {
        //Shape s = new Shape();   Interfaces cannot have instances.
        Shape r = new Rectangle(6, 8);
        System.out.println(r.area());
        System.out.println(r.diameter());
        System.out.println(r.perimeter());
        //  System.out.println(r.numSides());  r can't see numSides
        r = new Circle(10);
        System.out.println(r.area());
        System.out.println(r.diameter());
        System.out.println(r.perimeter());
        Polygon p = new Rectangle(5,12);
        System.out.println(p.area());
        System.out.println(p.diameter());
        System.out.println(p.perimeter());
        System.out.println(p.numSides());
        ArrayList<Shape> al = new ArrayList<>();
        al.add(new Rectangle(6,8));
        al.add(new Circle(10));
        al.add(new Rectangle(5,12));
        System.out.println(al);
        System.out.println(silly(p));
    }
    public static double silly(Shape s)
    {
        return s.area() + s.diameter() + s.perimeter();
    }
}