Как нарисовать прямоугольник в System.Windows.Forms?

{$reference System.Drawing.dll}
{$reference System.Windows.Forms.dll}
uses System.Windows.Forms, System.Drawing;
begin
 var f1:=new Form;
 f1.Size:=new System.Drawing.Size(500,500);
 for var i:=1 to 25 do
 Rectangle.Create(i*10,i*10,f1.Size.Width-i*10,f1.Size.Height-i*10);
 Application.Run(f1);
end.

{$reference System.Drawing.dll}
{$reference System.Windows.Forms.dll}
uses System.Windows.Forms, System.Drawing;
 
procedure frmPaint(sender: Object; e: PaintEventArgs);
begin
  var f := sender as Form;
  for var i := 1 to 25 do
    e.Graphics.DrawRectangle(new Pen(System.Drawing.Color.Red),
      i * 10, i * 10, f.Size.Width - 2 * i * 10, f.Size.Height - 2 * i * 10);
end;
 
begin
  var f1 := new Form;
  f1.Size := new System.Drawing.Size(500, 500);
  f1.Paint += frmPaint;
  Application.Run(f1);
end.