Click Trimetric
(Standard Views toolbar).
Click Structural
Member 
(Weldments
toolbar).
In the PropertyManager, under Selections:
Add an I-beam structural member along the sketch segments to define the rails on the bottom of the part. You change the pierce point of the I-beam profile to position the structural member properly.
Click Trimetric
(Standard Views toolbar).
Click Structural
Member (Weldments
toolbar).
In the PropertyManager, under Selections:
Select iso in Standard.
Select sb beam in Type.
Select 80 x 6 in Size.
Select the two new sketch segments for Path segments.
Click Right
(Standard Views toolbar).
In the PropertyManager, under Settings,
click Locate Profile.
The display zooms to the profile of the structural member. The default
pierce point centers the profile on the sketch segment.
