# What does an octahedron look like?

An octahedron is a polyhedron with eight faces. A regular octahedron can be composed of eight equilateral triangles, four forming each half, and meeting in the middle at a square.

Imagine a pyramid, with a square base. Rising up from each edge is an equilateral triangle that meets the other four triangles at the apex. Now, turn the pyramid over and add four more triangles to the other side the same way. You now have an octahedron.

For more information, and a rotating picture, please see the related link below.

### What shaped hole would you need for an octahedron to get through a shape sorter?

That's a really good question. It has several answers. You can put an octahedron through a square hole - just look at the octahedron point on. You can put an octahedron through a hole that's a regular hexagon - lay the octahedron down on a table on one of its triangles and look down on it and that's what you'll see. You can put an octahedron through a rhombus - to see that, look at…