Revit 2019.2 APIArc..::..XDirection Property Arc Class See Also Returns the X direction.Namespace: Autodesk.Revit.DBAssembly: RevitAPI (in RevitAPI.dll) Version: 19.0.0.0 (19.2.0.66)SyntaxC#public XYZ XDirection { get; }Visual BasicPublic ReadOnly Property XDirection As XYZ GetVisual C++public: property XYZ^ XDirection { XYZ^ get (); }See AlsoArc ClassAutodesk.Revit.DB Namespace