what pyramid has 4 triangular faces

A triangular pyramid has 4 triangular faces. It’s also called a tetrahedron.

Why

• All 4 faces are triangles.
• It has 4 vertices and 6 edges.
• Unlike a square pyramid, it does not have a square base.

In simple terms

If every face is triangular, the shape is a tetrahedron, which is the pyramid you’re describing.