length

Calculates the length of the given geometry. This planar measurement uses 2D Cartesian mathematics to compute the length. It is based upon the SpatialReference of the input geometry. If the input geometry is not using an 'distance preserving' spatial reference, the result can be inaccurate. You have two options available to calculate a more accurate result:

• Use a different spatial reference. Use the GeometryEngine.projectOrNull(Geometry, SpatialReference) method to project the geometry to a projected coordinate system that is better suited for area calculations. See Spatial references[https://developers.arcgis.com/documentation/spatial-references/] and Supported map projections[https://pro.arcgis.com/en/pro-app/latest/help/mapping/properties/list-of-supported-map-projections.htm] for more information.

• Use the geodetic equivalent, GeometryEngine.lengthGeodetic(Geometry, LinearUnit, GeodeticCurveType).

Supports true curves.