Problem 9 works

/*
 *  C# Program to Find a Number using Pythagoras Theorem
 */
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Text;
class Program
{
    static void Main(string[] args)
    {

        double a, b, c;
        bool answer = false;
        Stopwatch sw = new Stopwatch();
        sw.Start();
        for (int n = 0;answer ==false && n < 1000 ; n++)
        {
            a = n;
            Console.WriteLine(a);
            for (int i = 0; i < n; i++)
            {

                b = a - i;

            for (int x = 0; x < b; x++)
                {
                    c = b - x;
                    if (a == Math.Sqrt(b * b + c * c) && a + b + c == 1000)
                    {
                        double d = (a * b * c);
                        Console.WriteLine("Time to calculate in milliseconds : {0}", sw.ElapsedMilliseconds);
                        Console.WriteLine(d);
                        Console.ReadLine();

                    }

                }
            }
        }
        Console.WriteLine("This is a the end");
        Console.ReadLine();
    }

}