procedure TForm1.FormShow(Sender: TObject);
begin
// Draw a triangle polygon
With TIEPolylineLayer( ImageEnVect1.CurrentLayer ) do
begin
  ClearAllPoints();
  AddPoint( 500, 0 );
  AddPoint( 1000, 1000 );
  AddPoint( 0, 1000 );
  PolylineClosed := True;
end;
ImageEnVect1.Update();
end;

procedure TForm1.Button1Click(Sender: TObject);
var
  iShapePoints: array of TPoint;
begin
  SetLength( iShapePoints, 3 );
  iShapePoints[0] := Point( 500, 0 );
  iShapePoints[1] := Point( 1000, 1000 );
  iShapePoints[2] := Point( 0, 1000 ); 
  iLayer := ImageEnView1.LayersAdd(ielkPolyline);
  TIEPolylineLayer(ImageEnView1.Layers[iLayer]).SetPoints(iShapePoints, True);
  ImageEnView1.Update();
end;