using System;

public class Program

{

    public static void Main()

    {

    double x1,x2,x3,x4,y1,y2,y3,y4,b3d1,b3d2,b3d3,b3d4,allb3d;

        Console.WriteLine("enter x1");

        x1=double.Parse(Console.ReadLine());

        Console.WriteLine("enter y1");

        y1=double.Parse(Console.ReadLine());

        Console.WriteLine("x2=");

        x2=double.Parse(Console.ReadLine());

        Console.WriteLine("y2=");

        y2=double.Parse(Console.ReadLine());

        Console.WriteLine("enter x3");

        x3=double.Parse(Console.ReadLine());

        Console.WriteLine("enter y3");

        y3=double.Parse(Console.ReadLine());

        Console.WriteLine("enter x4");

        x4=double.Parse(Console.ReadLine());

        Console.WriteLine("enter y4");

        y4=double.Parse(Console.ReadLine());

        b3d1=Math.Sqrt((x1-x2)*(x1-x2) + (y1-y2)*(y1-y2));

        b3d2=Math.Sqrt((x2-x3)*(x2-x3) + (y2-y3)*(y2-y3));

        b3d3=Math.Sqrt((x3-x4)*(x3-x4) + (y3-y4)*(y3-y4));

        b3d4=Math.Sqrt((x4-x1)*(x4-x1) + (y4-y1)*(y4-y1));

        allb3d=b3d1+b3d2+b3d3+b3d4;

        Console.WriteLine("الضلع الاول = {0} الضلع الثاني ={1} الضلع الثالث = {2} الضلع الرابع = {3} المحيط = {4}",b3d1,b3d2,b3d3,b3d4,allb3d);

​

    }

}