This pink plastic model has an equilateral triangle for a base and three triangles on the sides that meet in a point. A thin pyramid with a quadrilateral base is attached to each side edge of this larger triangular pyramid. One edge of each thin pyramids coincides with an edge of the larger triangular pyramid. One short edges from each pyramid meets another thin pyramid at the top of the model. Many sides are coplanar. The entire model has white plastic threads around it. A mark on the bottom reads: 651.
According to Wheeler’s catalog, model 651 has ten vertices (e=10), eighteen edges (k=18), and nine faces, (f = 9) for an Euler characteristic of e – k + f = 1.
Models MA.304723.378 and MA.304723.362 have the same shape. Models MA.304723.377 and MA.304723.401 have the same shape. Models MA.304723.378 and MA.304723.401 are both marked 650. Models MA.304723.377 and MA.304723.362 are both marked 651.
A.H. Wheeler, "List of Models," Mathematics Collections, Non-accession number 1979.3002.83, NMAH.
Our collection database is a work in progress. We may update this record based on further research and review. Learn more about our approach to sharing our collection online.