my @fulls;
for my $area (@areas) {
    for my $short (@shorts) {
        push @fulls, "$short.area$area";
    }
}

##</code><code>##

my @fulls =
    map { my $area = $_; map "$_.area$area", @shorts }
    @areas;

##</code><code>##

my @fulls =
    map { my $short = $_; map "$short.area$_", @areas }
    @shorts;

##</code><code>##

use Algorithm::Loops qw( NestedLoops );

my @fulls = NestedLoops(
    [ \@areas, \@shorts ],
    sub { "$_[1].area$_[0]" },
);