You are probably looking for the $canvas->bbox() method. It has some quirks(like outline pixels being off), but it is usable. 
#!/usr/bin/perl
use Tk;
use strict;

my $x=10;
my $y=20;
my $x1=30;
my $y1=40;

my $mw=tkinit;
my $c=$mw->Canvas->pack;

my $rect = $c->createRectangle($x,$y,$x1,$y1,
               -fill=>'red' );

print "rect-> $x $y $x1 $y1\n";
my ($bx,$by,$bx1,$by1)= $c->bbox($rect);

print "bbox-> $bx $by $bx1 $by1\n";
MainLoop;

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In reply to Re^3: Fogetting Tk Canvas widgets by zentara
in thread Fogetting Tk Canvas widgets by merrymonk

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