Mayamatam 33.44

33.44

trayodaśāṃśakaṃ śreṣṭhaṃmadhye'ṣṭāṃśe tupūrvavat
triḥsaptāṃśe nijāyāme ṣaṭpañcacaturaṃśakam

And thirteen parts is superior, with eight parts intermediate as before. / When its own length is divided into twenty-one parts, [the width is] six, five, or four parts;