static void Main(string[] args)
{
// Rectangle Rec = new Rectangle(0,0);
// Rec.Display();
Square Sqr = new Square(0, 0);
Sqr.Display();
Triangle Tri = new Triangle(0, 0);
Tri.Display();
Octogon Oct = new Octogon(0, 0);
Oct.Display();
Console.ReadLine();
}