Do you have thicken? You could always carry on down the mesh route. Right click the mesh change to surface then thicken to whatever you need?

Yeah I'll do some pointers for you. Could you screen grab your menus? Click and drag them out to separate them and I will be able to see what you have.

The primitive thing should be changeable in the first tab of the inspector window. Turn this on by going to WINDOW, INSPECTOR. A new dialog box should pop up with options to edit sizes, line types and all this

Looks like you're into using extrude or sweep functions. The thicken I mentioned is in the boolean options so it's not in your version. Other option is have a look in power pack, do you have line normal to surface?

Since your triangle looks like it's on an angle you could do a line normal to the surface and then use the line as the extrude direction. If not set your work plane from 3 points. Select the 3 points around the triangle and then you can do a curve normal to surface/workplane. Then extrude/sweep using the curve.

I'm afraid I don't think you have anything as fast as push/pull in your version.

Or like you say use mesh extrude and then right click the mesh you've just extruded and 'change object type' then select solids. You'll probably end up with a dumb solid though by doing that.

I think when you mesh extrude you should get a extrude distance in the inspector bar which you can later edit, same goes for the normal extrude. Sweep would use the line length so that's another way to edit it quickly, change the length of the line

You can build from primitives, but why? Better to draw profiles, 2D shapes on a workplane that can be extruded, revolved or swept along paths or vectors. You can edit extrusion distances (make thinner or thicker) in inspector data properties, editing paths changes the length of sweeps. Faces of solids, even non-planar faces, can be extruded, revolved or swept in VC/Shark. That creates a new solid that you will add to the existing if it's to extend the part. Push/pull is what's called a "direct edit" tool, the transformed section doesn't have to be added, but I think that you do have "move face". Move face isn't exactly the same as push/pull, but move face isn't restricted to flat faces. Profiles can be used to make surfaces that can be thickened as Ugmentalcase suggested, but surfaces can also be created between curves that don't have to be planar, or have their endpoints coincident or meeting (depending on the type of surface you're creating). Surfaces are regarded as closed objects in VC/Shark, like profiles, and they can be extruded, swept or revolved as profiles can. Your extrusion or sweep of a face is capped at either end with the surface or face. Primitives can be convenient, but they're very limited compared to history-based, feature-based modelling, which is what VC/Shark is built to do. Those sound like jargon, but they let you change elements of your model without having to redo it from scratch. Done right, the model rebuilds itself with features from an earlier creation point changed, and appropriate changes to relationships with other features are made automatically. PowerPack has some useful tools, but they're gravy, not the meat and bones.