A square based pyramid.
The shape in question is called a square pyramid.
It is the base/face of a certain shape, as in a square, it would be the bottom line(the one on/closest to the ground).
When you place two square-based pyramids square to square, they form a shape known as a bipyramid. This configuration results in a three-dimensional shape with a square base and two apexes, one above and one below the base, connected by triangular faces. The overall shape resembles a diamond or a double-pointed figure.
A square!
A square based pyramid is a three dimensional shape with a square base, and four triangles (one from each side of the base) that meet at a point above the base. The shape has 5 vertices, 5 faces and 8 edges.
A shape with a square base and four triangular sides is a pyramid.
A square pyramid.
A Square Pyramid.
A pyramid has 1 square base.
The base
It's a pentagonal pyramid.
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?