using System;

 public class Program

 {

 public static void Main()

 {

 double AT, LA, LB, LC, LS;

 Console.WriteLine("Ingrese longitud A: ");

 LA = Convert.ToDouble(Console.ReadLine());

 Console.WriteLine("Ingrese longitud B: ");

 LB = Convert.ToDouble(Console.ReadLine());

 Console.WriteLine("Ingrese longitud C: ");

 LC = Convert.ToDouble(Console.ReadLine());

 LS = (LA + LB + LC) / 2;

 AT = Math.Pow(LS * (LS - LA) * (LS - LB) * (LS-LC),0.5);

 Console.WriteLine("Area del triangulo: " + AT);

 }

 }

​