Q: Context: When unspecified, a pyramid is usually assumed to be a regular square pyramid, like the physical pyramid structures. A triangle-based pyramid is more often called a tetrahedron.

Question: what do you call a pyramid with a triangular base?
Let's give stream of consciousness below

user
The relevant sentence in the passage is: A triangle-based pyramid is more often called a tetrahedron. So the answer is a tetrahedron.
assistant