Forked from https://github.com/gileCAD/GeometryExtensions to make a version available for AutoCAD and BricsCAD There are conditional symbols defined for each build of Debug and Release to suit AutoCAD or BricsCAD, choose the build you need for your platform.
Reference this assembly in AutoCAD .NET projects setting the Copy Locale property to True.
Download the assembly (GeometryExtensions.dll for AutoCAD 2013 an later).
See the documentation.