Concentric

<p><span class="one-click-content css-9sn2pa e10vl5dg6"><span class="one-click" data-term="having" data-linkid="nn1ov4">having&nbsp;</span>a&nbsp;<span class="one-click" data-term="common" data-linkid="nn1ov4">common&nbsp;</span><span class="one-click" data-term="center" data-linkid="nn1ov4">center,&nbsp;</span>as&nbsp;<span class="one-click" data-term="circles" data-linkid="nn1ov4">circles&nbsp;</span>or&nbsp;<span class="one-click" data-term="spheres" data-linkid="nn1ov4">spheres.</span></span></p>