Question

What are the minimum number of faces needed to form a 3d shape

Answer 1

In 2 dimensions it takes at least 3 sides to make a polygon, the triangle, and in 3 dimensions it takes at least 4 faces (so far as I'm aware) to make a polyhedron. Can this rule be generalized to higher dimensions, so that the minimum number of sides or faces to make a polytope in n-dimensions is equal to n+1? If so, is there a proof for it? And if not, is there a counterexample?