Exam 5. Triangle

namespace _1.Triangle
{
    using System;
    using System.Linq;

    public class Point
    {
        public int X { get; set; }

        public int Y { get; set; }
    }

    public class Triangle
    {
        public static void Main(string[] args)
        {
            checked
            {
                Point[] trianglePoints = new Point[3];
                for (int i = 0; i < trianglePoints.Length; i++)
                {
                    int pointX = int.Parse(Console.ReadLine());
                    int pointY = int.Parse(Console.ReadLine());
                    Point nextPoint = new Point { X = pointX, Y = pointY };
                    trianglePoints[i] = nextPoint;
                }

                double[] sidesTriangle = new double[trianglePoints.Length];
                for (int j = 0; j < sidesTriangle.Length; j++)
                {
                    sidesTriangle[j] = DistanceBetweenTwoPoints(trianglePoints[j], trianglePoints[(j + 1) % sidesTriangle.Length]);
                }

                bool isTriangle = (sidesTriangle[0] + sidesTriangle[1]) > sidesTriangle[2] && (sidesTriangle[1] + sidesTriangle[2]) > sidesTriangle[0] && (sidesTriangle[0] + sidesTriangle[2]) > sidesTriangle[1];

                if (isTriangle)
                {
                    Console.WriteLine("Yes");
                    double triangleArea = CalculateTriangleAreaByHeronFormula(sidesTriangle);
                    Console.WriteLine("{0:f2}", triangleArea);
                }
                else
                {
                    Console.WriteLine("No");
                    Console.WriteLine("{0:f2}", sidesTriangle[0]);
                }
            }
        }

        private static double CalculateTriangleAreaByHeronFormula(double[] sides)
        {
            checked
            {
                double perimeter = sides.Sum() / 2d;
                double area = perimeter;
                for (int i = 0; i < sides.Length; i++)
                {
                    area *= perimeter - sides[i];
                }

                area = Math.Sqrt(area);
                return area;
            }
        }

        private static double DistanceBetweenTwoPoints(Point point1, Point point2)
        {
            checked
            {
                double distance = Math.Sqrt(((point2.X - point1.X) * (point2.X - point1.X)) + ((point2.Y - point1.Y) * (point2.Y - point1.Y)));

                return distance;
            }
        }
    }
}