using System;
namespace task4
{
    public class Figure
    {
        public string FigureType;

        private Point[] p;

        public Figure(Point p1, Point p2, Point p3)
        {
            p = new Point[3];
            p[0] = p1;
            p[1] = p2;
            p[2] = p3;

            FigureType = "Triangle";
        }
        public Figure(Point p1, Point p2, Point p3, Point p4)
        {
            p = new Point[4];
            p[0] = p1;
            p[1] = p2;
            p[2] = p3;
            p[3] = p4;

            FigureType = "Rectangle";
        }
        public Figure(Point p1, Point p2, Point p3, Point p4, Point p5)
        {
            p = new Point[5];
            p[0] = p1;
            p[1] = p2;
            p[2] = p3;
            p[3] = p4;
            p[4] = p5;

            FigureType = "Pentagon";
        }

        public double getPerimeter()
        {
            double P = 0;

            if (FigureType == "Triangle")
            {
                for(byte i=0; i < p.Length-1; i++)
                {
                    P += Math.Sqrt(Math.Pow((p[i].X - p[i+1].X),2) + Math.Pow((p[i].Y - p[i+1].Y),2));
                }
                return P + Math.Sqrt(Math.Pow((p[0].X - p[p.Length - 1].X), 2) + Math.Pow((p[0].Y - p[p.Length - 1].Y), 2));
            }
            else if (FigureType == "Rectangle")
            {
                for (byte i = 0; i < p.Length-1; i++)
                {
                    P += Math.Sqrt(Math.Pow((p[i].X - p[i + 1].X), 2) + Math.Pow((p[i].Y - p[i + 1].Y), 2));
                }
                return P + Math.Sqrt(Math.Pow((p[0].X - p[p.Length - 1].X), 2) + Math.Pow((p[0].Y - p[p.Length - 1].Y), 2));
            }
            else if (FigureType == "Pentagon")
            {
                for (byte i = 0; i < p.Length-1; i++)
                {
                    P += Math.Sqrt(Math.Pow((p[i].X - p[i + 1].X), 2) + Math.Pow((p[i].Y - p[i + 1].Y), 2));
                }
                return P + Math.Sqrt(Math.Pow((p[0].X - p[p.Length - 1].X), 2) + Math.Pow((p[0].Y - p[p.Length - 1].Y), 2));
            }
            else
                return 0;
        }
    }
}