using System;

​

// Encapsulating the calculator functionality into a class

public class Calculator

{

    protected double result;

​

    public double Result

    {

        get { return result; }

    }

​

    public void Add(double num1, double num2)

    {

        result = num1 + num2;

    }

​

    public void Subtract(double num1, double num2)

    {

        result = num1 - num2;

    }

​

    public void Multiply(double num1, double num2)

    {

        result = num1 * num2;

    }

​

    public void Divide(double num1, double num2)

    {

        if (num2 != 0)

            result = num1 / num2;

        else

            Console.WriteLine("Error: Cannot divide by zero.");

    }

}

​

// Creating a specific type of calculator using inheritance

public class ScientificCalculator : Calculator

{

    public void Square(double num)

    {

        result = Math.Pow(num, 2);

    }

​

    public void SquareRoot(double num)

    {

        result = Math.Sqrt(num);

    }

}

​

public class Program

{

    public static void Main()

    {

        // Using the Calculator class

        Calculator calculator = new Calculator();

        calculator.Add(5, 3);

        Console.WriteLine("Result: " + calculator.Result);  // Output: Result: 8

​

        calculator.Subtract(10, 4);

        Console.WriteLine("Result: " + calculator.Result);  // Output: Result: 6

​

        // Using the ScientificCalculator class (inherited from Calculator)

        ScientificCalculator scientificCalculator = new ScientificCalculator();

        scientificCalculator.Square(5);

        Console.WriteLine("Result: " + scientificCalculator.Result);  // Output: Result: 25

​

        scientificCalculator.Divide(10, 2);

        Console.WriteLine("Result: " + scientificCalculator.Result);  // Output: Result: 5

    }

}