I asked around and was told the equation resembles Heron's formula, but I can't see it. The only part recognizable to me is <b^2+c^2-bc cos(A)> being most of the Law of Cosines.

Also, Latin ranguage, if I'm guessing rightly. The version I find on the western side of the web reads,
"Gram loquitur; Dia vera docet; Rhet verba colorat;
Mus canit; Ar numerat; Ge ponderat; Asti colit astra."