You are c# developer who is developing a windows application. you need to provide derived classes the ability to share common functionality with base classes but still define their own unique behavior. which object-oriented programming concept should you use to accomplish this functionality?

Polymorphism; the concept of one definition, but multiple implementations.

In C#, this is done using the 'abstract' and 'override' keywords.

Example:

abstract class Shape {

public abstract double area ();

}

class Square : Shape {

private double size;

public Square (double size = 0) {

this. size = size;

}

public override double area () {

return size * size;

}

}