procedure TForm1.Button1Click(Sender: TObject);
var
x,y: integer;
begin
image1.Canvas.Brush.Style:=bssolid;
image1.canvas.Rectangle(clientrect);
image1.Canvas.Brush.Style:=bsclear;
x:=20;
for y:= 1 to 5 do
    image1.Canvas.Rectangle(0,0+x*y,100-x*y,100);

end;

procedure TForm1.Button2Click(Sender: TObject);
var
x,y: integer;
begin
image1.Canvas.Brush.Style:=bssolid;
image1.canvas.Rectangle(clientrect);
image1.Canvas.Brush.Style:=bsclear;

x:=20;
for y:= 1 to 5 do
    image1.Canvas.Rectangle(0,0+x*y,0+x*y,100);

end;

procedure TForm1.Button3Click(Sender: TObject);
var
x,y,z: integer;
begin
image1.Canvas.Brush.Style:=bssolid;
image1.canvas.Rectangle(clientrect);
image1.Canvas.Brush.Style:=bsclear;

x:=20;
for z:= 1 to 5 do
    for y:= 0 to 4 do
        image1.Canvas.Rectangle(0+x*y,0,20+x*y,0+x*z);

end;