A triangular prism has a triangle for the base. Every cross-section parallel to the base is also a triangle.
A net of a triangular prism is shown here.
A triangular prism has 5 faces, 6 vertices and 9 edges. To build a rectangular prism with construction materials, we would need 3 rectangles and 2 triangles that join at the edges to make a closed three-dimensional shape or 9 edge pieces and 6 corner pieces to make a frame of the prism.
A triangular prism can also be called a pentahedron because it has five faces. Penta means five.