A line in space. 
   Namespace:   Autodesk.Revit.DB  
  Assembly:   RevitAPI  (in RevitAPI.dll) Version: 2015.0.0.0 (2015.0.0.0) 
Syntax
Inheritance Hierarchy
  System Object  
Autodesk.Revit.DB APIObject
Autodesk.Revit.DB GeometryObject
Autodesk.Revit.DB Curve
Autodesk.Revit.DB Line
 
 Autodesk.Revit.DB APIObject
Autodesk.Revit.DB GeometryObject
Autodesk.Revit.DB Curve
Autodesk.Revit.DB Line