public static double Distance( Geometry geometry1, Geometry geometry2 )
Public Shared Function Distance ( geometry1 As Geometry, geometry2 As Geometry ) As Double
Planar measurements of distance and area can be extremely inaccurate if using an unsuitable spatial reference. Ensure that you understand the potential for error with the geometry's spatial reference. If you need to calculate more accurate results consider using a different spatial reference, or using the geodetic equivalent, DistanceGeodetic(MapPoint, MapPoint, LinearUnit, AngularUnit, GeodeticCurveType). See the document Introduction to Spatial References for more information about spatial references.
This distance calculation is based upon the SpatialReference of the input geometries. Although some projections are better than others for preserving distance, it will always be distorted in some areas of the map. Distortion may be negligible for large scale maps (small areas) that use a suitable map projection.