Question

this is a

1. triangular prism
2. triangular pyramid
3. square pyramid

Explanation:

A triangular prism has two triangular bases and three rectangular lateral - faces. A triangular pyramid has a triangular base and three triangular lateral - faces that meet at a single point (apex). A square pyramid has a square base and four triangular lateral - faces. The given figure has a triangular base and triangular lateral - faces meeting at an apex, so it is a triangular pyramid.

Answer:

1. triangular pyramid