This .NET class wraps the AcGeBoundedPlane ObjectARX class. It represents a bounded planar parametric surface.

Autodesk.AutoCAD.Geometry.Entity3d
    Autodesk.AutoCAD.Geometry.Surface
        Autodesk.AutoCAD.Geometry.PlanarEntity
            Autodesk.AutoCAD.Geometry.BoundedPlane

Public sealed Class BoundedPlane
Inherits PlanarEntity

public sealed class BoundedPlane : PlanarEntity;