Which can be found in \MasterDocs\Cad\Revit\Waterman Library\Families\Structural Framing and is called W_FRA_C-Rectangular Taper Beam
As you would expect it is fully parametric and allows you to enter the Haunch details and adjust the end angle if it is sloping.![](//1.bp.blogspot.com/_WEO55byaZbQ/Ss77c60ZwOI/AAAAAAAAARo/COXmh_Whadg/s320/Taper+P.png)