# calculate length and width of paper strip
# based on diameter of circle of inner edge
sub NumberCrunch()
{
   my ($diameter) = @_;
   my $L = $diameter * 0.58778525229;
   my $W = $L * 0.951056516; # W = L * cos(18)
   my $total_length = $L * 47.725424859;
   return ($total_length, $W);
}
...
my ($TotalLength, $PaperWidth) = NumberCrunch($Diameter);