in C++ using Visual Studio

3. (General math) a. Create a base class named Rectangle containing length and width data members. From this class, derive a class named Box with another data member named depth. The member functions of the base class Rectangle should consist of a constructor and an area() function. The derived class Box should have a constructor, a volume () function, and an override function named area() that returns the surface area of the box. b. Include the classes constructed for Exercise 3a in a working C++ program. Have your pro- gram call all the member functions in each class and verify the results manually