ArcGIS Pro 3.0 API Reference Guide
ArcGIS.Core.Geometry Namespace / IGeometryEngine Interface / Union Method

Union Method (IGeometryEngine)
Overload List
OverloadDescription
Constructs the set-theoretic union of the input geometries.  
Constructs the set-theoretic union of the input geometries.  
Requirements

Target Platforms: Windows 11, Windows 10, Windows 8.1

ArcGIS Pro version: 2.0 or higher.
See Also