static void Main(string[] args)
        {
            Console.WriteLine("Test Shape");
            Choturvuj ayotokhetro = new Choturvuj {
                height = 12, width = 5
            };
            Choturvuj borgo = new Choturvuj {
                height = 5, width = 5
            };
            Britto britto = new Britto {
                radius = 4
            };

            GetArea(ayotokhetro);
            GetArea(borgo);
            GetArea(britto);
        }
 static internal void GetArea(Shape s)
 {
     if (s is Choturvuj)
     {
         Choturvuj c = s as Choturvuj;
         if (c.height == c.width)
         {
             Console.WriteLine("Area of Choturvuj = " + c.height * c.width);
         }
         else
         {
             Console.WriteLine("Area of Choturvuj = " + c.height * c.width);
         }
     }
     else if (s is Britto)
     {
         Britto c = s as Britto;
         Console.WriteLine("Area of the Britto = " + (Shape.PI * (c.radius * c.radius)));
     }
 }