This .NET class wraps the AcGeLineSeg2d ObjectARX class. It represents a bounded line segment in 2D space.

Autodesk.AutoCAD.Geometry.Entity2d
    Autodesk.AutoCAD.Geometry.Curve2d
        Autodesk.AutoCAD.Geometry.LinearEntity2d
            Autodesk.AutoCAD.Geometry.LineSegment2d

Public sealed Class LineSegment2d
Inherits LinearEntity2d

public sealed class LineSegment2d : LinearEntity2d;