tetrahedral

To get a sense of why this fact about geodesics is true on four of the five Platonic solids, we’ll take a “tumbling” approach to these paths, and we’ll switch over to a tetrahedral world where tumbling paths are a little easier to study.

To the south, 27 E., is a tetrahedral peak, which our guide called Ngoma-dingding.

The spores of this species are spheroid-tetrahedral, the three radiating angles marked with slender vittæ, or bands.

It crystallizes in the cubic system; with regular octahedral and tetrahedral cleavages; spec.