Just personal preference here, but I prefer to use "shift" instead of picking off arguments from @_, like this:

  sub coor {
    my $c = shift; # get 1st argument
    my $d = shift; # get 2nd argument
    return ( $c + 109, $d + 5 );
  }
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And, the OP should use "use strict;" and either "-w" on the first perl line or "use warnings;".