Steve, you can model this type of part with either the PartDesign or GSD workbenches by using the Multi-Sections tool. One method would be to make a Multi-Section Surface between the 135 deg bent section and the flat section with tangencies, and then use ThickSurface to make a solid with thickness. (let me know if you need more details)

I don't think the Sheetmetal workbench will work for this part, because it only works with constant bend angles and you have a varying angle. Maybe someone else might be able to tell us otherwise.