PlanarFaceYVector Property

public XYZ YVector { get; }

Public ReadOnly Property YVector As XYZ
	Get

public:
property XYZ^ YVector {
	XYZ^ get ();
}

member YVector : XYZ with get

Note that the cross product of X-vector and Y-vector may result in the reverse of the FaceNormal vector depending upon how Revit has structured this particular face.