Cortesian system if a triangle

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;

namespace novo2
{
    class Program
    {
        static void Main(string[] args)
        {
            int aX = int.Parse(Console.ReadLine());
            int aY = int.Parse(Console.ReadLine());
            int bX = int.Parse(Console.ReadLine());
            int bY = int.Parse(Console.ReadLine());
            int cX = int.Parse(Console.ReadLine());
            int cY = int.Parse(Console.ReadLine());
            string n = "No";
            string f = "Yes";
            double a = Math.Sqrt(Math.Pow((cX - bX), 2) - Math.Pow((cY - bY), 2));
            double b = Math.Sqrt(Math.Pow((cX - aX), 2) - Math.Pow((cY - aY), 2));
            double c = (Math.Sqrt(Math.Pow((bX - aX), 2) + Math.Pow((bY - aY), 2)));
            float area = aX * bY + bX * cY + cX * aY - bX * aY - cX * bY - aX * cY;
            if (area == 0)
            {
                Console.WriteLine(n);
            Console.WriteLine("{0:0.00}", c);
            }
            else
            {
                float triangle = area / 2;
                Console.WriteLine(f);
                Console.WriteLine("{0:0.00}", triangle);
            }

            }
                }
                 }