Pup tent or lean-to
Roof tops
The Pentagon Department of defense office building
If you asking where you'd find them in the real world - Binoculars and telescopes are two examples.
A pyramid like in Egypt or something like that. Or a triangular tent
Pup tent or lean-to
A real life example is a Toblerone chocolate bar which is in the shape of a triangular prism.
roof
Roof of a house
tent
A solid brick is a rectangular prism. (this one example of many)
stuff
A pencil.
A basic camping tent, a house roof, and the iconic Toblerone box.
A gaming die.
Roof tops
An Amicelli box! THIS IS NOT TRUE IT IS HEXAGONAL!!