[Google Maps v3] Get Rectangle area with computeArea

gistfile1.txt

var _computeRectangleArea = function(bounds) {
  if (!bounds) {
    return 0;
  }
  var sw = bounds.getSouthWest();
  var ne = bounds.getNorthEast();
  var southWest = new google.maps.LatLng(sw.lat(), sw.lng());
  var northEast = new google.maps.LatLng(ne.lat(), ne.lng());
  var southEast = new google.maps.LatLng(sw.lat(), ne.lng());
  var northWest = new google.maps.LatLng(ne.lat(), sw.lng());
  return google.maps.geometry.spherical.computeArea([northEast, northWest, southWest, southEast]) / (1000000);
};

Thank you.