ArcGIS API for JavaScript ^3.29

require([
  "esri/geometry/Polygon", "esri/SpatialReference", ... 
], function(Polygon, SpatialReference, ... ) {
  var poly = new Polygon(new SpatialReference({wkid:4326}));
  ...
});

require([
  "esri/geometry/Polygon", ... 
], function(Polygon, ... ) {
  var polygonJson  = {"rings":[[[-122.63,45.52],[-122.57,45.53],[-122.52,45.50],[-122.49,45.48],
    [-122.64,45.49],[-122.63,45.52],[-122.63,45.52]]],"spatialReference":{"wkid":4326 }};
  var polygon = new Polygon(polygonJson);
  ...
});

var singleRingPolygon = new Polygon([[50, 0], [150, 20], [150, -20], [50,0]]);

var map;

require([
  "esri/InfoTemplate",
  "esri/layers/FeatureLayer",
  "esri/map",
  "esri/tasks/query", "dojo/domReady!"
], function (InfoTemplate, FeatureLayer, Map, Query){

  map = new Map("map", {
    basemap: "topo",
    center: [-122.45, 37.75], // longitude, latitude
    zoom: 10
  });

  var infoTemplate = new InfoTemplate("Attributes", "${*}");

  var countiesFeatureLayer = new FeatureLayer("http://sampleserver6.arcgisonline.com/arcgis/rest/services/USA/MapServer/3",
    {
      mode: FeatureLayer.MODE_ONDEMAND,
      infoTemplate: infoTemplate,
      outFields: ['*']
    });
  var highwaysFeatureLayer = new FeatureLayer("http://sampleserver6.arcgisonline.com/arcgis/rest/services/USA/MapServer/1",
    {
      mode: FeatureLayer.MODE_ONDEMAND,
      infoTemplate: infoTemplate,
      outFields: ['*']
    });

  map.on("load", function (){
    map.addLayer(countiesFeatureLayer);
    map.addLayer(highwaysFeatureLayer);

    var query = new Query();
    query.geometry = map.extent;
    query.spatialRelationship = Query.SPATIAL_REL_ENVELOPEINTERSECTS;
    query.returnGeometry = true;
    query.outFields = ["*"];

    countiesFeatureLayer.queryFeatures(query, function (featureSet){
      var polygon = featureSet.features[0].geometry;
      // populate the Geometry cache by calling getExtent()
      var polygonExtent = polygon.getExtent();
      console.log("polygonExtent", polygonExtent);
      console.log("polygon.cache._extent", polygon.cache._extent);

      for (var i = 0; i < featureSet.features.length; i  ) {
        var feature = featureSet.features[i];
        console.log("Polygon geometry cache, %o", feature.geometry.cache);
        feature.geometry.clearCache();
        console.log("Polygon geometry clear cache, %o", feature.geometry.cache);
        // Break out of the loop after the first result
        break;
      }
    });

    highwaysFeatureLayer.queryFeatures(query, function (featureSet){
      var line = featureSet.features[0].geometry;
      // populate the Geometry cache by calling getExtent()
      var lineExtent = line.getExtent();
      console.log("lineExtent", lineExtent);
      console.log("line.cache._extent", line.cache._extent);

      for (var i = 0; i < featureSet.features.length; i  ) {
        var feature = featureSet.features[i];
        console.log("Line geometry cache, %o", feature.geometry.cache);
        feature.geometry.clearCache();
        console.log("Line geometry clear cache, %o", feature.geometry.cache);
        // Break out of the loop after the first result
        break;
      }
    });

  });
});

require([
  "esri/geometry/Polygon", "esri/SpatialReference", ... 
], function(Polygon, SpatialReference, ... ) {
  var polygon = new Polygon(new SpatialReference({wkid:4326}));
  polygon.addRing([[-180,-90],[-180,90],[180,90],[180,-90],[-180,-90]]);

  polygon.addRing([[-83,35],[-74,35],[-74,41],[-83,41],[-83,35]]);
  ...
});

  var selectionPolygon = Polygon.fromExtent(selectionExtent);

var taxLotExtent = selectedTaxLot.geometry.getExtent();

require([
  "esri/geometry/Polygon", ... 
], function(Polygon, ... ) {
  var polygon = new Polygon( ... );
  var clockwise = polygon.isClockwise(polygon.rings[0]);
  ...
});

require([
  "esri/geometry/Polygon", ... 
], function(Polygon, ... ) {
  var polygon = new Polygon( ... );
  var isIntersecting = polygon.isSelfIntersecting(polygon);
  ...
});