Как изменить выносную линию у размера?

public static void Main()
        {
            Document doc = Application.DocumentManager.MdiActiveDocument;
            Database db = doc.Database;
            Editor ed = doc.Editor;

            try
            {
                Transaction tr = db.TransactionManager.StartTransaction();
                using (tr)
                {
                    BlockTable bt = (BlockTable)tr.GetObject(db.BlockTableId, OpenMode.ForRead);
                    BlockTableRecord btr = (BlockTableRecord)tr.GetObject(db.CurrentSpaceId, OpenMode.ForWrite, false);
                    PromptSelectionOptions pso = new PromptSelectionOptions();
                    pso.MessageForAdding = "\nВыберите размеры: ";

                    SelectionFilter sf = new SelectionFilter(
                        new TypedValue[] { new TypedValue((int)DxfCode.Start, "Dimension") });
                    PromptSelectionResult psr = ed.GetSelection(pso, sf);
                    if (psr.Status != PromptStatus.OK) { return; }
                    foreach (ObjectId objId in psr.Value.GetObjectIds())
                    {
                        Dimension dim = (Dimension)objId.GetObject(OpenMode.ForWrite, false);
                        if (dim.GetType().Name.Equals("RotatedDimension"))
                        {
                            Point3dCollection strp = new Point3dCollection();
                            dim.GetStretchPoints(strp);

                        }// if
                    }// foreach
                    tr.Commit();
                }// tr
            }// try
            catch (System.Exception ex)
            { System.Windows.Forms.MessageBox.Show(ex.Message); }
        }// main