<a href="https://en.wikipedia.org/wiki/1-simplex" class="extiw" title="en:1-simplex">en:1-simplex</a> family graph, in A1 Coxeter plane
<a href="//commons.wikimedia.org/wiki/User:Tomruen" title="User:Tomruen">Tomruen</a>
<span class="int-own-work" lang="en">Own work</span>