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.\n\nQuestion: what do you call a pyramid with a triangular base? Okie... think carefully first, then make a decision:
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