A simple drawing, explaining the polygons in <a href="https://en.wikipedia.org/wiki/Central_place_theory" class="extiw" title="en:Central place theory">Central place theory</a>
<a href="//commons.wikimedia.org/wiki/User:Thpanagos" title="User:Thpanagos">Thpanagos</a>
<span class="int-own-work" lang="en">Own work</span>