package Rectangle;
use strict;
use warnings;
use Polygon;
our @ISA = ('Polygon');

#Rectangles take two lengths
sub new {
    my $class=shift;
    my ($len, $wid) = @_;
    my $obj = $class->SUPER::new(($len, $wid) x 2);
    bless $obj, $class;
}

#accessors
sub length {
    my $obj = shift;
    my $length = shift;
    if (defined $length){
        @{$obj}[0,2] = ($length) x 2;
    }
    return $obj->[0];
}

sub width {
    my $obj = shift;
    my $width = shift;
    if (defined $width){
        @{$obj}[1,3] = ($width) x 2;
    }
    return $obj->[1];
}

sub area {
    my $obj = shift;
    return $obj->length() * $obj->width();
}

package Square;
use strict;
use warnings;
our @ISA = ('Rectangle');

sub new {
    my $class = shift;
    my $length = shift;
    my $obj = $class->SUPER::new(($length) x 2);
    bless $obj, $class;
}

sub length {
    my $obj = shift;
    my $length = shift;
    if (defined $length){
        @{$obj} = ($length) x 4;
    }
    return $obj->[0];
}

sub area {
    my $obj = shift;
    return $obj->length() ** 2;
}

1;