help with oop code

[nhlfan]

Hello guys,

I am doing the following exercise:

a) Create a base class named Rectangle that contains length and width data members. From this class, derive a class named Box having an additional data member named depth. The method members of the base Rectangle class should consist of a constructor and have an area( ) method. The derived Box class should have a constructor and an override method named area( ) that returns the surface area of the box and a volume( ) method.

b) Include the classes constructed for Exercise 8a in a working Java program. Have your program call all of the member methods in each class and explain the result when the area method is called using two Box objects.

I have 3 separate files : Rectangle.java, Box.java, and UsingShapes.java
This is what I have so far:

Rectangle.java

Code:

public class Rectangle
{
 
protected double length;
protected double width;
 
public Rectangle (double lh, double wh)
{
 
length = lh;
width = wh;		
 
}
 
public double area()
{
	return(length * width);
}
 
}

Box.java

Code:

public class Box {
protected double depth;	
 
public Box (double lh, double wh, double dh)
 
{
super(lh);
super(wh);
depth = dh;	
}
 
public double area()
 
{
	return ((2*super.area)+(2*(dh*super(lh))+ (2*(dh*super(wh))))); //surface area of box = 2(h*w) + 2(h*l) + 2(w*l)
}
 
public double volume()
{
	return (depth * super.area());
}
 
}

UsingShapes.java (File which runs the other 2 files)

Code:

public class UseShapes {
public static void main (String[] args) {
 
Rectangle rect1 = new Rectangle(2,4);
Box bv = new Box(5,5,5);
	
Box boxOne = new Box(1, 2, 3);
Box boxTwo = new Box(4, 5, 6);
 
System.out.println("The area of the rectangle is " + rect1.area);
System.out.println("The volume of the box is " + bv.volume);
 
System.out.println("The surface area of boxOne is " +boxOne.area);
System.out.println("The surface area of boxTwo is " +boxTwo.area);	
	
	}
}

Any help? Thanks alot

[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.