Natyashastra
द्वौ तालावर्धतालश्च पादयोरन्तरं भवेत् । तयोः समस्थितस्त्वेकः त्र्यश्रः पक्षस्थितोऽपरः ॥ ५२॥
The distance between the feet should be two Tālas and a half. One foot should be placed in a natural position, while the other should be obliquely positioned in a triangular stance.
english translation
dvau tAlAvardhatAlazca pAdayorantaraM bhavet । tayoH samasthitastvekaH tryazraH pakSasthito'paraH ॥ 52॥
hk transliteration by Sanscript