Here is polygon shapes we made out of clay and popsicles. We learnt this formular. E=v+F-2. E is for edges V for vertices and F for faces. It really helps to know if you got the faces vertices and edges correct. For our triangular prism we got 6 corners 9 edges and 5 faces.
For the pentagonal pyramid there were 6 corners, 10 edges and 6 faces. Here it is.