C# program to check if number is Triangle Number.
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; // ? 2017 TheFlyingKeyboard and released under MIT License // theflyingkeyboard.net namespace CheckIfNumberIsSquare { class Program { static void Main(string[] args) { int num; Console.Write("Enter a number: "); num = Convert.ToInt32(Console.ReadLine()); if (isSquare(8 * num + 1)) { Console.Write("Number is triangle number"); } else { Console.Write("Number is not triangle number"); } Console.ReadKey(); } static bool isSquare(int n) { for (int i = 0; i < n / 2 + 2; i++) { if (i * i == n) { return true; } } return false; } } }
C# Check If Number Is Triangle Number