using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

        Rectangle r = new Rectangle

            {

                P1 = { X = 0, Y = 1 },

                P2 = { X = 2, Y = 3 },

                P3 = { X = 2 }

            };

        Console.WriteLine($"{r}");

    }

}

​

public class Rectangle

{

    public Rectangle()

    {

        P1 = new Point(); //default Point for demo purpose

        P2 = new Point(); //default Point for demo purpose

        P3 = new Point(){X=10, Y=12}; //default Point for demo purpose

    }

​

    public Point P1 { get; set; }

    public Point P2 { get; set; }

    public Point P3 { get; set; }

    public override string ToString(){

        return string.Format("P1: {0}, P2: {1}, P3: {2}", P1, P2, P3);

    }

}

​

public class Point

{

    public int X { get; set; }

    public int Y { get; set; }

    public override string ToString(){

        return string.Format("{{X= {0}, Y= {1}}}", X, Y);

    }

}