Square frustum

The square frustum is a polyhedron with 2 squares of different size and 4 isosceles trapezoids as faces. It can be thought of as a cube with one face scaled up about its center, distorting the four faces adjacent to it. It can also be thought of as a square pyramid with its one order-4 vertex truncated.

A special case of the square frustrum with one base edge length twice the other, and lacing length equal to the small base edge length, appears in the study of convex triamond polyhedra.

Vertex coordinates
A square frustrum with base lengths $a$ and $b$ and height $h$ has the coordinates
 * $$\left(\pm a,\,\pm a,\,0\right),$$
 * $$\left(\pm b,\,\pm b,\,h\right).$$