A 3D shape could be:
A square!
A shape with a square base and four triangular sides is a pyramid.
A pyramid has 1 square base.
a square * * * * * That would be a square pyramid! A triangular pyramid would have ... wait for it ... a TRIANGULAR base! Worth waiting for, wasn't it?
a a square based pentagon
A pyramid with a square base is called a square pyramid. It is a three-dimensional shape that has a square as its base and four triangular faces that meet at a point called the apex.
The shape in question is called a square pyramid.
A square!
A shape with a square base and four triangular sides is a pyramid.
A pyramid has 1 square base.
The base
a square * * * * * That would be a square pyramid! A triangular pyramid would have ... wait for it ... a TRIANGULAR base! Worth waiting for, wasn't it?
A square based pyramid.
a a square based pentagon
A square pyramid is a pyramid whose base is in the shape of a square.
The shape you're referring to is called a "square pyramid" when viewed from its base, but when viewed from certain angles, especially when oriented vertically, it can resemble a diamond shape. In geometric terms, it maintains its classification as a square pyramid, which has a square base and triangular faces that converge at a point. The diamond-like appearance is often seen in perspective or as a projection rather than a change in its geometric classification.
A square.