A really big triangle made by aliens.
I never have seen the word "pryrimid" before but "pyramid" is a geometric shape.
the shape is formed by a polygon (many sided planar figure) and a point (vertex) not coplanar with the polygon. Join the vertex with the sides of the polygon with triangular faces and yoyu have a pyramid. The pyramid with the fewest sides is a tetrahedron (a triangular pyramid). The regular tetrahedron is the simplest of the solids.
The square pyramid has been used since antiquity for buildings.
Some very big stone pyramids are in Egypt, Mexico and China.