#!/usr/bin/perl

use strict;
use warnings;

our %opts;
my $lookup;

for (@ARGV) {$opts{$1}=$2 if (/([ABC]{1})=(\d+\.?\d*)/)}
$lookup = join '', sort keys %opts;
die "I need two sides!\n" unless (length($lookup)==2);
my $lut = {
   'AB' => sub {return 'C='.sqrt($opts{A}**2+$opts{B}**2)},
   'AC' => sub {return 'B='.sqrt($opts{C}**2-$opts{A}**2)},
   'BC' => sub {return 'A='.sqrt($opts{C}**2-$opts{B}**2)},
};
print &{$lut->{$lookup}}, "\n";

#!/usr/bin/perl
 -w

print "\n Phytagorasrechner fuer C:\n\n";

print "\n Wert fuer A (in cm/ m): ";
chomp($a = <>);

print "\n Wert fuer B (in cm/ m): ";
chomp($b = <>);



$c =sqrt( $a**2 + $b**2);
printf("\n\n Berechneter Wert fuer C mit 2 Nachkommastellen: %.2f cm/ m\n", $c);