What's the benefit i get if i use Method Overriding ?

What's the benefit i get if i use Method Overriding ?

The derived class or sub class can have its own business logic in it..

Say for example, considering a real time example..

Let us say we have a class where some features of bank transactions are

 defined..

Now, we want to write our own bank transactions using already existing

 methods defined in the class but extending its behaviiour and with some

 modifications...

this is the sitaution where we inherit the class and overrride the

 methods which are required to suit our business requirement...

method overriding will be used to redefine the base class methods 

functionality in child classes... so base class and child clas method 

have different functioality.... It will work differently depends on the

 object used to call that one...

In some situations we want to have a class that has types(specially methods) that can possibly be modified in the derived class. In such situation we declare the method in the base class as virtual and precede the same method in the derived class with 'override' keyword
Consider the following code in which situation is that, a base class method Area() returns square of a parameter and suppose we want to extend this method in the derived class sothat this square may just be multiplied by a constant pi(3.142) so that it can return area of a circle: