#!/usr/bin/perl -w
use strict;
CHOICE: print "
    This is Unit 6 - Quadrilaterals and Polygons.\n
    For the Final Exam, you will have to know the\n
    properties of all quadrilaterals and how to\n
    prove that a given shape is any quadrilateral.\n
    To access the Quadrilateral Information Database,\n
    type 'Quads.' To access the Casio-Maxim Quadrilateral\n
    Identification Algorithm, type 'crazy Maxim.'\n
    Type 'quit' to exit Unit 6.\n
    Type your choice.\n\n";
my $Choice = <STDIN>;
chomp $Choice;
if($Choice =~ /quit/i) {print "\nBye.\n\n"; exit;}
if($Choice =~ /quads/i) {require "Quadrilaterals.pl";}
if($Choice =~ /crazy maxim/i) {require "CMQIA.pl";}