Get the area of a polygon

area.js

var points = [
[33.950649172363335,-117.40098863840103],
[33.95048007651844,-117.40097254514694],
[33.95035992926655,-117.40098059177399],
[33.950355479365065,-117.4010556936264],
[33.95048675136076,-117.40105032920837],
[33.95066363449239,-117.40104496479034]];
var area = function(points){
  var length = points.length;
  var arr = [];
  for(var i = 0; i < length - 1; i += 1){
    var one = points[i][0] * points[i + 1][1];
    var two = points[i][1] * points[i + 1][0];
    arr.push(one - two);
  }
  var result = 0;
  for(i = 0; i < arr.length; i += 1){
    result += arr[i];
  }
  return (result < 0) ? -1 * result / 2 : result / 2;
}
console.log(area(points));