Final answer:
There are no triangular bases among the 3 square pyramids and 2 pentagonal pyramids.
Step-by-step explanation:
A triangular base is a base in the shape of a triangle. To determine the number of triangular bases among 3 square pyramids and 2 pentagonal pyramids, we need to consider the bases of each pyramid.
A square pyramid has a square base, so it does not have a triangular base.
A pentagonal pyramid has a pentagonal base, so it also does not have a triangular base.
Therefore, among the 3 square pyramids and 2 pentagonal pyramids, there are no triangular bases.