[hardwired]

From this class, derive a class named Box
This means that Box extends (from) Rectangle.

Code:

public class UseShapesRx
{
    public static void main (String[] args)
    {
        RectangleRx rect1 = new RectangleRx(2,4);
        BoxRx bv = new BoxRx(5,5,5);
        System.out.println("The area of the rectangle is " + rect1.area());
        System.out.println("The volume of the box is " + bv.volume());

        BoxRx boxOne = new BoxRx(1, 2, 3);
        BoxRx boxTwo = new BoxRx(4, 5, 6);
        System.out.println("The surface area of boxOne is " +boxOne.area());
        System.out.println("The surface area of boxTwo is " +boxTwo.area());	
    }
}

public class BoxRx extends RectangleRx
{
    protected double depth;	

    public BoxRx(double lh, double wh, double dh)
    {
        super(lh, wh);
        depth = dh;	
    }
 
    public double area()
    {
        //surface area of box = 2(h*w) + 2(h*l) + 2(w*l)
        double area = 2*(length*width + width*depth + length*depth);
        return area;
    }

    public double volume()
    {
        return width * length * depth;
    }
}

No changes in Rectangle class but name changed to RectangleRx for this.