ArcGIS Pro 2.7 API Reference Guide
Cut Method (GeometryEngine)
Example 

ArcGIS.Core.Geometry Namespace > GeometryEngine Class : Cut Method
The polygon or polyline to cut.
The cutting line.
Splits this geometry into parts. A polyline will be split into two parts at most.
Syntax

Parameters

multipart
The polygon or polyline to cut.
cutter
The cutting line.

Return Value

An IEnumerable<Geometry> representing the cut geometries.
Exceptions
ExceptionDescription
Either multipart or cutter or both are null or empty.
The method is not implemented for GeometryBag.
Incompatible spatial references between the input geometries.
Remarks
When a polyline/polygon is cut, it is split where it intersects the cutter polyline. If a geometry is not cut, the returned IEnumerable<Geometry> will be empty.

GeometryEngine Cut

Example
SpatialReference sr = SpatialReferences.WGS84;

List<MapPoint> list = new List<MapPoint>();
list.Add(MapPointBuilder.CreateMapPoint(1.0, 1.0, sr));
list.Add(MapPointBuilder.CreateMapPoint(1.0, 4.0, sr));
list.Add(MapPointBuilder.CreateMapPoint(4.0, 4.0, sr));
list.Add(MapPointBuilder.CreateMapPoint(4.0, 1.0, sr));

List<Geometry> cutGeometries;

LineSegment line = LineBuilder.CreateLineSegment(MapPointBuilder.CreateMapPoint(0, 0, sr), MapPointBuilder.CreateMapPoint(3, 6, sr));
Polyline cutter = PolylineBuilder.CreatePolyline(line);

// polyline
Polyline polyline = PolylineBuilder.CreatePolyline(list);
bool isSimple = GeometryEngine.Instance.IsSimpleAsFeature(polyline);
cutGeometries = GeometryEngine.Instance.Cut(polyline, cutter) as List<Geometry>;

Polyline leftPolyline = cutGeometries[0] as Polyline;
Polyline rightPolyline = cutGeometries[1] as Polyline;

// leftPolyline.Points[0] = 1, 2
// leftPolyline.Points[1] = 1, 4
// leftPolyline.Points[2] = 2, 4

// rightPolyline.Points.Count = 5
// rightPolyline.Parts.Count = 2

ReadOnlySegmentCollection segments0 = rightPolyline.Parts[0];
// segments0[0].StartCoordinate = 1, 1
// segments0[0].EndCoordinate = 1, 2

ReadOnlySegmentCollection segments1 = rightPolyline.Parts[1];
// segments1.Count = 2
// segments1[0].StartCoordinate = 2, 4
// segments1[0].EndCoordinate = 4, 4
// segments1[1].StartCoordinate = 4, 4
// segments1[1].EndCoordinate = 4, 1

// polygon 
Polygon polygon = PolygonBuilder.CreatePolygon(list);
isSimple = GeometryEngine.Instance.IsSimpleAsFeature(polygon);
cutGeometries = GeometryEngine.Instance.Cut(polygon, cutter) as List<Geometry>;
Requirements

Target Platforms: Windows 10, Windows 8.1

See Also

Reference

GeometryEngine Class
GeometryEngine Members