#!/usr/bin/perl -w 

use Tk;
use strict;  
                                                                    
my $mw = MainWindow->new;
my $c = $mw->Canvas(
-width => 500,
-height => 500,
-background =>'blue'
);

$c->pack(-expand => 1, -fill => 'both');
my $rect=$c->createOval(100, 150, 120, 170, -fill => 'yellow'); 

MainLoop;