If you make the bottom of the pile accessible in some manner (like with a door), it&#x27;s more efficient to withdraw the grain from that point due to gravity.<p>Peripherally related, this pyramid talk finally made me look up &quot;critical angle of repose&quot; of various materials: <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Angle_of_repose#Angle_of_repose_of_various_materials" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Angle_of_repose#Angle_of_repos...</a>.<p>The Great Pyramids are around the 50° mark, where modern wheat&#x27;s angle of repose is roughly half that (27°). That&#x27;s not to say a pyramid-like structure <i>couldn&#x27;t</i> be used to store wheat—just that the shape of these particular pyramids don&#x27;t directly mimic the free-standing angle that a wheat mound would form.