Geometrical diagram and 3D representation of a "capsule". Parameters shown are: <i><b>r</b></i> for radius, <i><b>a</b></i> for side length, and <i><b>C</b></i> for for circumference.
<a href="//commons.wikimedia.org/wiki/User:Orionist" title="User:Orionist">Orionist</a>
<span class="int-own-work" lang="en">Own work</span>