ArcGIS Pro 2.6 API Reference Guide
PolygonBuilder Constructor(IEnumerable<Coordinate2D>,SpatialReference)
Example 

ArcGIS.Core.Geometry Namespace > PolygonBuilder Class > PolygonBuilder Constructor : PolygonBuilder Constructor(IEnumerable<Coordinate2D>,SpatialReference)
Coordinates for the first ring.
(Optional) The SpatialReference. The default value is null.
Initializes a new instance of the PolygonBuilder class. This method must be called on the MCT. Use QueuedTask.Run.
Syntax

Parameters

coordinates
Coordinates for the first ring.
spatialReference
(Optional) The SpatialReference. The default value is null.
Exceptions
ExceptionDescription
This method or property must be called within the lambda passed to QueuedTask.Run.
coordinates is null.
Example
List<Coordinate2D> outerCoordinates = new List<Coordinate2D>();
outerCoordinates.Add(new Coordinate2D(10.0, 10.0));
outerCoordinates.Add(new Coordinate2D(10.0, 20.0));
outerCoordinates.Add(new Coordinate2D(20.0, 20.0));
outerCoordinates.Add(new Coordinate2D(20.0, 10.0));

// Builder constructors need to run on the MCT.
ArcGIS.Desktop.Framework.Threading.Tasks.QueuedTask.Run(() =>
{
  // use the PolygonBuilder as we wish to manipulate the parts
  using (PolygonBuilder pb = new PolygonBuilder(outerCoordinates))
  {
    Polygon donut = pb.ToGeometry();
    double area = donut.Area;       // area = 100

    // define the inner polygon as anti-clockwise
    List<Coordinate2D> innerCoordinates = new List<Coordinate2D>();
    innerCoordinates.Add(new Coordinate2D(13.0, 13.0));
    innerCoordinates.Add(new Coordinate2D(17.0, 13.0));
    innerCoordinates.Add(new Coordinate2D(17.0, 17.0));
    innerCoordinates.Add(new Coordinate2D(13.0, 17.0));

    pb.AddPart(innerCoordinates);
    donut = pb.ToGeometry();

    area = donut.Area;    // area = 84.0

    area = GeometryEngine.Instance.Area(donut);    // area = 84.0
  }
});
Requirements

Target Platforms: Windows 10, Windows 8.1, Windows 7

See Also

Reference

PolygonBuilder Class
PolygonBuilder Members
Overload List