using System;

public class Program

{

    public static void Main()

    {

        start:

        Console.WriteLine("Welcome!! Let's get started, enter 1 , 2, or 3");

        Console.WriteLine("Please choose an option:");

        Console.WriteLine("1. Find missing leg");

        Console.WriteLine("2. Find hypotenuse");

        Console.WriteLine("3. Quit");

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

        switch (choice)

        {

            case 1:

                Console.WriteLine("Enter value of first leg");

                double leg1 = double.Parse(Console.ReadLine());

                Console.WriteLine("Enter value of second leg");

                double leg2 = double.Parse(Console.ReadLine());

                double hypotenuse = pyth(leg1, leg2);

                Console.WriteLine("The hypotenuse of the triangle is " +hypotenuse);

                break;

            case 2:

                Console.WriteLine("Enter length of the leg");

                double userleg = double.Parse(Console.ReadLine());

                Console.WriteLine("Enter the length of the hypotenuse");

                double userhyp = double.Parse(Console.ReadLine());

                double missingleg = leg(userleg, userhyp);

                Console.WriteLine("The missing leg of the triangle is " +missingleg);

                break;

            case 3:

                Console.WriteLine("Goodbye");

                return;

        }

        Console.WriteLine("Press any key to continue");

        Console.ReadLine();

        Console.Clear();

        goto start;

    }

    static private double pyth(double a, double b)

    {

        double a2 = a*a;

        double b2 = b *b;

        return Math.Sqrt(a2+b2);

    }

    private static double leg(double b, double c)

    {

        double b2 = b*b;

        double c2 = c*c;

        return Math.Sqrt(c2 - b2);

    }

    }