Mathematics Pictures Cool and comfy seats in the Umea University MIT building! I can�t remember� what is the name for a 3-D solid that has a hole or point of convergence of the sides and faces in the centre like this? I wonder if a person�s body would fill the Centre so that the volume matches the volume of an associated solid? How much fun would it be to do my math homework in �chairs� like this on a rug like this!?! :-) Jamie PyperJuly 3, 2018September 19, 2019