using System;

public class Program

{

    public static void Main()

    {

     int angle_1, angle_2, angle_3, sum;

     Console.Write("Angle 1 of Triangle:");

     angle_1 = int.Parse(Console.ReadLine());

     Console.Write("Angle 2 of Triangle:");

     angle_2= int.Parse(Console.ReadLine());

     Console.Write("Angle 3 of Triangle:");

     angle_3= int.Parse(Console.ReadLine());

    sum = angle_1 + angle_2 + angle_3;

    if (sum == 180)

    {

    Console.WriteLine("The triangle is Valid");

    }

    else

    {

    Console.WriteLine("The triangle is Invalid");

    }

}

​