Isosceles trapezoid

The isosceles trapezoid is a trapezoid with a single symmetry axis. Equivalently, it is a trapezoid with the same leg lengths and base angles.

If the legs intersect, the figure may more precisely be called a crossed isosceles trapezoid.

In vertex figures
Every polygonal antiprism has an isosceles trapezoid as its vertex figure. The vertex figures for the crossed antiprisms are themselves crossed, and thus crossed isosceles trapezoids.