Returns the normal to the plane in which the arc is defined.
Namespace: Autodesk.Revit.DB
Assembly: RevitAPI (in RevitAPI.dll) Version: 20.0.0.0 (20.0.0.377)
Namespace: Autodesk.Revit.DB
Assembly: RevitAPI (in RevitAPI.dll) Version: 20.0.0.0 (20.0.0.377)