Natyashastra
इह प्रेक्ष्यागृहं दृष्ट्वा धीमता विश्वकर्मणा । त्रिविधः सन्निवेशश्च शास्त्रतः परिकल्पितः ॥ ७॥
Here, after observing the audience hall, the wise architect Vishwakarma has conceived the threefold arrangement, as outlined in the scriptures.
english translation
iha prekSyAgRhaM dRSTvA dhImatA vizvakarmaNA । trividhaH sannivezazca zAstrataH parikalpitaH ॥ 7॥
hk transliteration by Sanscript