use strict;
use warnings;
use Math::Geometry::Planar;

my $polygon = Math::Geometry::Planar->new;

my $points = [[0,0],
              [1,0],
              [1,1],
              [0,1],
         ];

$polygon->points($points) ;
 
print "Perimeter:",$polygon->perimeter,"\n" ;
print "Area:     ",$polygon->area,"\n" ;

for my $point ( [.725,.396], [2,3], [1,1] ) {
  if ($polygon->isinside($point)) { 
    print "point @{$point} is inside\n" ;
  }else{
    print "point @{$point} is outside\n" ;
  }
}
[download]

Perimeter:4
Area:     1
point 0.725 0.396 is inside
point 2 3 is outside
point 1 1 is outside
[download]