https://commons.wikimedia.org/wiki/File:Square_antiprism.png
Autor: Tomruen
Licencia: The copyright holder of this file, Robert Webb
(https://en.wikipedia.org/wiki/User:RobertCWebb), allows anyone to use
it for any purpose, provided that the copyright holder is properly attributed.
Redistribution, derivative work, commercial use, and all other use is permitted.
Attribution must be given to Robert Webb's Stella software:
http://www.software3d.com/Stella.php