Definition of pentagon:
- "Amusements in Mathematics", Henry Ernest Dudeney.
The vaulting of the most easterly bay connects with that of the pentagon, thus leaving three remaining bays to vault; two form a sexpartite vault, and the third, nearest the transept, a quadripartite.- "Cathedrals of Spain", John A. (John Allyne) Gade.
- "The Flying Saucers are Real", Donald Keyhoe.