I would bet on a regular hexagon for the base, and I would call the shape a hexagonal pyramid.
There is more than one answer to this. Could be a hexagonal pyramid (a pyramid with triangular sides and a hexagon base).
Duh, didn't I call it a hexagonal pyramid?
The shape you are describing is a pyramid. A pyramid is a three-dimensional geometric shape that has a polygonal base and triangular faces that meet at a common vertex called the apex. In your case, the base of the pyramid is a polygon, and the faces are all triangular. To identify this shape as a pyramid, you need to recognize that it meets the criteria of having a triangular base and triangular faces that share a common apex.
