using System;

​

public class Program

{

    static private double formula1(double x, double y)

    {

        return Math.Sqrt(x * x + y * y);

    }

​

    static private double formula2(double x2, double y2)

    {

        return Math.Sqrt(y2 * y2 - x2 * x2);

    }

​

    public static void Main()

    {

        string random = " ";

        while (random != "no" && random != "No")

        {

    Console.Clear();

    Console.WriteLine("Do you want to find a missing leg or do you want to find the hypotenuse?");

    Console.WriteLine("Enter 1 for a hypotenuse or please enter 2 for a missing leg.");

    int sans = int.Parse(Console.ReadLine());

    if (sans == 1)

        {

        Console.WriteLine("Enter your first leg value:");

        string a = Console.ReadLine();

        double a1;

        if (double.TryParse(a, out a1))

            {

            Console.WriteLine("Enter your second leg value:");

            string b = Console.ReadLine();

            double b1;

            if (double.TryParse(b, out b1))

            {

                if (a != "" && b != "" && a1 > 0 && b1 > 0)

                    {

                    Console.WriteLine("Your hypotenuse is " + formula1(a1, b1));

                    Console.WriteLine("");

                    Console.WriteLine("Press any other key to restart or e to exit.");

                    random = Console.ReadLine();

                }

                else

                    {

                    Console.WriteLine("Enter a value that is greater than 0. Press any value to restart the program or press e to exit.");

                    random = Console.ReadLine();

            }

                }

            else

            {

                Console.WriteLine("Please enter a appropriate value. Press ENTER to restart or press e to exit.");

                random = Console.ReadLine();

        }

            }

            else

        {

            Console.WriteLine("Please enter a appropriate value. Press ENTER to restart or e to exit.");

            random = Console.ReadLine();

    }

        }

        else if (sans == 2)

    {

        Console.WriteLine("Please enter your leg value:");

        string c = Console.ReadLine();

        double c1;

        if (double.TryParse(c, out c1))

    {

        Console.WriteLine("Please enter your hypotenuse value:");

        string d = Console.ReadLine();

        double d1;

        if (double.TryParse(d, out d1))

    {

        if (c != "" && d != "" && d1 > c1 && c1 > 0 && d1 > 0)

    {

        Console.WriteLine("Your missing leg is " + formula2(c1, d1));

        Console.WriteLine("Press any other key to restart or press e to exit.");

        random = Console.ReadLine();

    }

        else if (d1 <= 0 || c1 <= 0)

    {

        Console.WriteLine("Please enter a value greater than 0. Press 'enter' to restart or press e to exit.");

        random = Console.ReadLine();

    }

        else if (d1 <= c1)

    {

        Console.WriteLine("Please enter a hypotenuse that is greater than the leg. Press ENTER to restart or press e to exit.");

        random = Console.ReadLine();

    }

        }

        else

    {

        Console.WriteLine("Please enter a valid value. Press ENTER to restart or press e to exit.");

        random = Console.ReadLine();

    }

        }

        else

        {

        Console.WriteLine("Please enter a valid value. Press ENTER to restart or press e to exit.");

        random = Console.ReadLine();

    }

        }

        else

    {

        Console.WriteLine("Please enter a valid value. Press ENTER to restart or press e to exit.");

        random = Console.ReadLine();

        }

        }

    }

}