Answer:
class Rectangle:  
    
    def __init__(self, length, width):
        self.length = length
        self.width = width
        
    
    def area(self):
        area = self.length*self.width
        return area
    
    
class Box (Rectangle):
    
    def __init__(self, length, width, height):
        super().__init__(length, width)
        self.height = height
        
    def volume(self):
        volume = self.length * self.width * self.height
        return volume
    
    def area(self):
        area = 2*(self.length*self.width) + 2*(self.length*self.height) + 2*(self.width*self.height)
        return area
rec_1 = Rectangle(2,4)
box_1 = Box(2,2,6)
print(box_1.length)
print(box_1.area())
    
print(rec_1.length)
print(rec_1.area())
Explanation:
The programming language used is python.
class Rectangle
The class Rectangle is created with attributes length and width.
The class attributes are initialized using the __init__ constructor. 
In the rectangle class, a method/function is declared to return the area of the rectangle.
class Box
This class is a child of rectangle and it inherits all its attributes and methods,
It has an additional attribute of depth and its constructor is used to initialize it.
The class contains a volume function, that returns the volume and an override function 'area()' that displaces the area from the parent class.
Finally, some instances of both classes are created.