RecursiveSqrt

using System;
using System.Numerics;

namespace _03.SquareRoot
{
    class Program
    {
        public static decimal Sqrt(int number, decimal root)

        {
            if (Math.Abs(root * root - number) <= 0.00000000001M)
                return root;

            return Sqrt(number, root - ((root * root) - number) / (2 * root));
        }

        static void Main(string[] args)
        {

            decimal root = Sqrt(12345, 10);

            Console.WriteLine(root);
        }
    }
}