// pt
MapPoint pt = MapPointBuilderEx.CreateMapPoint(1.0, 3.0, SpatialReferences.WebMercator);
double len = GeometryEngine.Instance.ShapePreservingLength(pt); // len = 0
List<MapPoint> pts = new List<MapPoint>();
pts.Add(MapPointBuilderEx.CreateMapPoint(1.0, 1.0, 3.0));
pts.Add(MapPointBuilderEx.CreateMapPoint(1.0, 3.0, 3.0));
pts.Add(MapPointBuilderEx.CreateMapPoint(3, 3, 3.0));
pts.Add(MapPointBuilderEx.CreateMapPoint(3.0, 1.0, 3.0));
// multipoint
Multipoint mPt = MultipointBuilderEx.CreateMultipoint(pts);
len = GeometryEngine.Instance.ShapePreservingLength(mPt); // len = 0
// polyline
Polyline polyline = PolylineBuilderEx.CreatePolyline(pts, SpatialReferences.WGS84);
len = GeometryEngine.Instance.ShapePreservingLength(polyline);
// polygon
Polygon polygon = PolygonBuilderEx.CreatePolygon(pts, SpatialReferences.WGS84);
len = GeometryEngine.Instance.ShapePreservingLength(polygon);
polyline = PolylineBuilderEx.CreatePolyline(new[]
{
MapPointBuilderEx.CreateMapPoint( -170, 0),
MapPointBuilderEx.CreateMapPoint( 170, 0)
}, SpatialReferences.WGS84);
var length_meters = GeometryEngine.Instance.ShapePreservingLength(polyline); // , LinearUnits.Meters);
var length_miles = GeometryEngine.Instance.ShapePreservingLength(polyline, LinearUnit.Miles);
// length_meters - 37848626.869713023
// length_miles - 23518.046402579574