require(["esri/geometry/Circle"], (Circle) => { /* code goes here */ });
import Circle from "@arcgis/core/geometry/Circle.js";
esri/geometry/Circle
A circle is a Polygon created by specifying a center point and a radius. The point can be provided as a Point object or an array of latitude/longitude values.
The SpatialReference of the center will determine the spatial reference of the circle. If you provide an array of longitude/latitude coordinates as the center, the spatial reference will default to WGS84 (wkid 4326). You cannot set the spatialReference property of the circle itself. It must always be set in the center point.
 See also
const circleGeometry = new Circle({
center: [ 113, 36 ],
geodesic: true,
numberOfPoints: 100,
radius: 100,
radiusUnit: "kilometers"
});
view.graphics.add(new Graphic({
geometry: circleGeometry,
symbol: {
type: "simplefill",
style: "none",
outline: {
width: 3,
color: "red"
}
}
}));
Constructors

Parameterproperties Objectoptional
See the properties for a list of all the properties that may be passed into the constructor.
Property Overview
Name  Type  Summary  Class 

Object  The cache is used to store values computed from geometries that need to be cleared or recomputed upon mutation.  Geometry  
Point  The center point of the circle.  Circle  
Point  The centroid of the polygon.  Polygon  
String  The name of the class.  Accessor  
Extent  The extent of the geometry.  Geometry  
Boolean  Applicable when the spatial reference of the center point is either set to Web Mercator (wkid: 3857) or geographic/geodesic (wkid: 4326).  Circle  
Boolean  Indicates if the geometry has M values.  Geometry  
Boolean  Indicates if the geometry has zvalues (elevation).  Geometry  
Boolean  Checks to see if polygon rings cross each other and indicates if the polygon is selfintersecting, which means the ring of the polygon crosses itself.  Polygon  
Number  This value defines the number of points along the curve of the circle.  Circle  
Number  The radius of the circle.  Circle  
String  Unit of the radius.  Circle  
Number[][][]  An array of rings.  Polygon  
SpatialReference  The spatial reference of the geometry.  Geometry  
String  The string value representing the type of geometry.  Polygon 
Property Details

The center point of the circle. The center must be specified either as a Point or an array of longitude/latitude coordinates. The spatial reference of the center will determine the spatial reference of the circle. If you provide an array of longitude/latitude coordinates, the spatial reference will default to WGS84 (wkid 4326).

geodesic
geodesic Boolean

Applicable when the spatial reference of the center point is either set to Web Mercator (wkid: 3857) or geographic/geodesic (wkid: 4326). When either of those spatial references is used, set geodesic to
true
to minimize distortion. Other coordinate systems will not create geodesic circles. Default Value:false

hasZ
InheritedPropertyhasZ Boolean
Inherited from Geometry 
Indicates if the geometry has zvalues (elevation).
Zvalues defined in a geographic or metric coordinate system are expressed in meters. However, in local scenes that use a projected coordinate system, vertical units are assumed to be the same as the horizontal units specified by the service.

numberOfPoints
numberOfPoints Number

This value defines the number of points along the curve of the circle.
 Default Value:60

radius
radius Number

The radius of the circle.
 Default Value:1000

radiusUnit
radiusUnit String

Unit of the radius.
Possible Values:"feet""kilometers""meters""miles""nauticalmiles""yards"
 Default Value:meters

Inherited from Polygon

An array of rings. Each ring is a twodimensional array of numbers representing the coordinates of each vertex in the ring in the spatial reference of the view. The first vertex of each ring should always be the same as the last vertex. Each vertex is an array of two, three, or four numbers. The table below shows the various structures of a vertex array.
Case Vertex array without z and without m [x, y] without z and with m [x, y, m] with z and without m [x, y, z] with z and with m [x, y, z, m] Example//3D polygon rings with mvalues (note that the second ring does not have mvalues defined for it) const rings = [ [ // first ring [97.06138,32.837,35.1,4.8], [97.06133,32.836,35.2,4.1], [97.06124,32.834,35.3,4.2], [97.06138,32.837,35.1,4.8] // same as first vertex ], [ // second ring [97.06326,32.759,35.4], [97.06298,32.755,35.5], [97.06153,32.749,35.6], [97.06326,32.759,35.4] // same as first vertex ] ]; const polygon = new Polygon({ hasZ: true, hasM: true, rings: rings, spatialReference: { wkid: 4326 } });

spatialReference
InheritedPropertyspatialReference SpatialReferenceautocast
Inherited from Geometry 
The spatial reference of the geometry.
 Default Value:WGS84 (wkid: 4326)
Method Overview
Name  Return Type  Summary  Class 

Adds one or more handles which are to be tied to the lifecycle of the object.  Accessor  
Polygon  Adds a ring to the Polygon.  Polygon  
Circle  Creates a deep clone of Circle.  Circle  
Boolean  Checks on the client if the input point is inside the polygon.  Polygon  
*  Creates a new instance of this class and initializes it with values from a JSON object generated from an ArcGIS product.  Geometry  
Point  Returns a point specified by a ring and point in the path.  Polygon  
Boolean  Returns true if a named group of handles exist.  Accessor  
Polygon  Inserts a new point into the polygon.  Polygon  
Boolean  Checks if a Polygon ring is clockwise.  Polygon  
Removes a group of handles owned by the object.  Accessor  
Point[]  Removes a point from the polygon at the given  Polygon  
Point[]  Removes a ring from the Polygon.  Polygon  
Polygon  Updates a point in the polygon.  Polygon  
Object  Converts an instance of this class to its ArcGIS portal JSON representation.  Geometry 
Method Details

Inherited from Accessor
Since: ArcGIS Maps SDK for JavaScript 4.25Accessor since 4.0, addHandles added at 4.25. 
Adds one or more handles which are to be tied to the lifecycle of the object. The handles will be removed when the object is destroyed.
// Manually manage handles const handle = reactiveUtils.when( () => !view.updating, () => { wkidSelect.disabled = false; }, { once: true } ); this.addHandles(handle); // Destroy the object this.destroy();
ParametershandleOrHandles WatchHandleWatchHandle[]Handles marked for removal once the object is destroyed.
groupKey *optionalKey identifying the group to which the handles should be added. All the handles in the group can later be removed with Accessor.removeHandles(). If no key is provided the handles are added to a default group.

addRing
InheritedMethodaddRing(points){Polygon}
Inherited from Polygon 
Adds a ring to the Polygon. The ring can be one of the following: an array of numbers or an array of points. When added the index of the ring is incremented by one.
ParameterA polygon ring. The first and last coordinates/points in the ring must be the same. This can either be defined as an array of Point geometries or an array of XY coordinates.
ReturnsType Description Polygon Returns the polygon with the new ring included.

contains
InheritedMethodcontains(point){Boolean}
Inherited from Polygon 
Checks on the client if the input point is inside the polygon. A point on the polygon line is considered inside.
Parameterpoint PointThe point to test whether it is contained within the testing polygon.
ReturnsType Description Boolean Returns true
if the point is located inside the polygon.

Creates a new instance of this class and initializes it with values from a JSON object generated from an ArcGIS product. The object passed into the input
json
parameter often comes from a response to a query operation in the REST API or a toJSON() method from another ArcGIS product. See the Using fromJSON() topic in the Guide for details and examples of when and how to use this function.Parameterjson ObjectA JSON representation of the instance in the ArcGIS format. See the ArcGIS REST API documentation for examples of the structure of various input JSON objects.
ReturnsType Description * Returns a new instance of this class.

getPoint
InheritedMethodgetPoint(ringIndex, pointIndex){Point}
Inherited from Polygon 
Returns a point specified by a ring and point in the path.
ParametersringIndex NumberThe index of the ring containing the desired point.
pointIndex NumberThe index of the desired point within the ring.
ReturnsType Description Point Returns the point at the specified ring index and point index.

hasHandles
InheritedMethodhasHandles(groupKey){Boolean}
Inherited from AccessorSince: ArcGIS Maps SDK for JavaScript 4.25Accessor since 4.0, hasHandles added at 4.25. 
Returns true if a named group of handles exist.
ParametergroupKey *optionalA group key.
ReturnsType Description Boolean Returns true
if a named group of handles exist.Example// Remove a named group of handles if they exist. if (obj.hasHandles("watchviewupdates")) { obj.removeHandles("watchviewupdates"); }

insertPoint
InheritedMethodinsertPoint(ringIndex, pointIndex, point){Polygon}
Inherited from Polygon 
Inserts a new point into the polygon.
ParametersringIndex NumberThe index of the ring in which to insert the point.
pointIndex NumberThe index of the point to insert within the ring.
The point to insert.
ReturnsType Description Polygon Returns the updated polygon.

isClockwise
InheritedMethodisClockwise(ring){Boolean}
Inherited from Polygon 
Checks if a Polygon ring is clockwise.
ParameterA polygon ring. The first and last coordinates/points in the ring must be the same. This can either be defined as an array of Point geometries or an array of XY coordinates.
ReturnsType Description Boolean Returns true
if the ring is clockwise andfalse
for counterclockwise.

Inherited from Accessor
Since: ArcGIS Maps SDK for JavaScript 4.25Accessor since 4.0, removeHandles added at 4.25. 
Removes a group of handles owned by the object.
ParametergroupKey *optionalA group key or an array or collection of group keys to remove.
Exampleobj.removeHandles(); // removes handles from default group obj.removeHandles("handlegroup"); obj.removeHandles("otherhandlegroup");

setPoint
InheritedMethodsetPoint(ringIndex, pointIndex, point){Polygon}
Inherited from Polygon 
Updates a point in the polygon.
ParametersringIndex NumberThe index of the ring containing the point to update.
pointIndex NumberThe index of the point to update within the ring.
The new point geometry.
ReturnsType Description Polygon Returns the updated polygon.

toJSON
InheritedMethodtoJSON(){Object}
Inherited from Geometry 
Converts an instance of this class to its ArcGIS portal JSON representation. See the Using fromJSON() guide topic for more information.
ReturnsType Description Object The ArcGIS portal JSON representation of an instance of this class.