This .NET class wraps the AcDb3PointAngularDimension ObjectARX class. 

The Point3AngularDimension class represents the angular dimension defined by three points (as opposed to two lines) within AutoCAD.

Autodesk.AutoCAD.DatabaseServices.DBObject
    Autodesk.AutoCAD.DatabaseServices.Entity
        Autodesk.AutoCAD.DatabaseServices.Dimension
            Autodesk.AutoCAD.DatabaseServices.Point3AngularDimension

Public Class Point3AngularDimension
Inherits Dimension

public class Point3AngularDimension : Dimension;

When a newly created dimension entity is first closed, an anonymous block (an BlockTableRecord that contains all the appropriate line, arc, arrowhead solids, text, among others, and with *D as the block name prefix) will automatically be created for it to reference for display.

DBObject, Entity