Abstract Class ************** Sample ====== :: abstract class absClass1 { public abstract int AddTwoNumbers(int Num1, int Num2); public abstract int MultiplyTwoNumbers(int Num1, int Num2); } abstract class absClass2 : absClass1 { public override int AddTwoNumbers(int Num1, int Num2) { return Num1+Num2; } } class absDerived : absClass2 { public override int MultiplyTwoNumbers(int Num1, int Num2) { return Num1*Num2; } } Note: - You need to use the ``override`` keyword when you override a method.