This class represents a Normal constraint node in the owning Assoc2dConstraintGroup. 

Currently it can only be applied between a line and circle(or arc).

Autodesk.AutoCAD.DatabaseServices.ConstraintGroupNode
    Autodesk.AutoCAD.DatabaseServices.GeometricalConstraint
        Autodesk.AutoCAD.DatabaseServices.NormalConstraint

Public Class NormalConstraint
Inherits GeometricalConstraint

public class NormalConstraint : GeometricalConstraint;