Polyhedron's formula helped me well on my class. I came up with something relevant to the said formula cause it's hard to solve a problem with only given only the number of faces of a regular polyhedron. So i made one of mine and tried to prove a lot of time to see if my formula was incorrect or not but it turns out that the formula i discovered worked pretty well. The formula has something to do with the polygon being used on the polyhedron.