use strict; # DO THIS! (by the way, you missed that one..)
use warnings; # haha and that too..

use Lingua::EN::Sentence;

my $page_sentence_count = 45; # 45 sentences per page!

my $sentences=get_sentences($text);	## Get the sentences.
for (my $scount = 0; $scount < scalar @$sentences; $scount++) {
  unless ($scount % $page_sentence_count) {
    print "Next page!\n";
    # do whatever you want here (say, open next file etc)
  }
  print $sentences->[$scount] . "\n";
}