- Polyhedron (Wikipedia)
In geometry, a polyhedron (pl.: polyhedra or polyhedrons; from Greek πολύ (poly-) ‘many’, and ἕδρον (-hedron) ‘base, seat’) is a three-dimensional shape with flat polygonal faces, straight edges and sharp corners or vertices.
- G-type star (Wikipedia)
G-type stars, including the Sun, have prominent spectral lines H and K of Ca II, which are most pronounced at G2. They have even weaker hydrogen lines than F, but along with the ionized metals, they have neutral metals. There is a prominent spike in the G band of CN molecules. Class G main-sequence stars make up about 7.5%, nearly one in thirteen, of the main-sequence stars in the solar neighborhood. There are 21 G-type stars within 10pc.