Ipsius autem theatri conformatio sic est facienda, uti, quam magna futura est perimetros imi, centro medio conlocato circumagatur linea rutundationis, in eaque quattuor scribantur trigona paribus lateribus; intervallis extremam lineam circinationis, tangant, quibus etiam in duodecim signorum caelestium astrologia ex musica convenientia astrorum ratiocinantur.
The plan of the theatre is to be thus arranged: that the centre is to be taken, of the dimension allotted to the orchestra at the ground level. The circumference is to be drawn; and in it four equilateral triangles are to be described touching the circumference at intervals (just as in the case of the twelve celestial signs, astronomers calculate from the musical division of the constellations).
final_alignments\Vitruvius_Architecture_Book_5.json