Et ad summam ita est gubernandum, uti, linea cum ad imum gradum et ad summum extenta fuerit, omnia cacumina graduum angulosque tangat; ita vox non inpedietur.
In brief the section of the theatre is to be so managed that if a line is drawn touching the lowest and the top rows, it shall also touch the front angles of all the rows. Thus the voice will not be checked.
final_alignments\Vitruvius_Architecture_Book_5.json