I am trying to write a simple code using object oriented concepts, but could not.

Can anybody please help.

File name : Mycalc.pm
-------------------------------
#!/usr/bin/perl
Package Mycalc;

sub _area {
my $length = shift;
my $breadth = shift;
return $length * $breadth;
}
sub _perimeter {
my $length = shift;
my $breadth = shift;
return 2 *( $length + $breadth );
}

1;
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File name : test.pl
#!/usr/bin/perl
use Mycalc;

my $area = &_area(5,6);
print $area;
------------
Getting errors
Undefined subroutine &main::_area called at test.pl line 4.