It is a pyramid with a flat base on top.
Time didn't allow him to read the entire novel, so he simply presented a truncated version.
A Causeway in a PYRAMID is a long passage going into the burial chamber
It is a pyramid that has a triangle as its base. The pyramids of Egypt are all built on square bases.
The answer depends on what you wish to work out: the angles, height, surface area, volume. Also, you need more information: the vertical or inclined height and whether or not the pyramid is a right pyramid.
The correct name for a 3D triangular pyramid is a 'TETRAHEDRON. It has FOUR(4) faces.