unit a55;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TForm1 = class(TForm)
    Button1: TButton;
    Edit1: TEdit;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    procedure luk(xc,yc,r:integer);

  end;

var
  Form1: TForm1;

implementation

procedure tform1.luk(Xc,yc,r:integer);
 var
x,y:integer;
a:real;
begin
a:=0;
repeat
x:=round(xc+r*cos(a));
y:=round (yc - r*sin(a));
canvas.Pixels[x,y]:=clred;
a:=a+1/r;
until
a>=2*pi;
end;


procedure TForm1.Button1Click(Sender: TObject);
var
xc,yc,r:integer;
begin
xc:=clientwidth div 2;
yc:=clientheight div 2;
r:=strtoint(edit1.Text);
luk(xc,yc,r);

end;

end.