public static void Main()
        {
            Delegates_demo3 obj  = new Delegates_demo3();
            rectangle       del3 = null;

            del3 += new rectangle(obj.rectangle_area);
            del3 += new rectangle(obj.rectangle_perimeter);

            del3(4, 4);
            Console.WriteLine();

            del3(5, 4);
        }
 public void Delegates3_DemoTest()
 {
     Delegates_demo3.Main();
 }