Negative area value

[stevenvar]

Using module Polygon :

open Polygon
let _ =
  let l = [(0.,0.);(0.,1.);(1.,1.);(1.,0.)] in
  let points = List.map (fun (x,y) -> Point.make x y) l in
  area points |> print_float 

returns -1

[ghilesZ]

fixed. Thanks