The Science of the Shulba: A Study in Early Hindu Geometry c20.9

c20.9

In the Śulba, a surd is technically called *karaṇī*. Thus *dvi-karaṇī*-means √2, *tri-karaṇī* =√3, *tṛtīya-karaṇī* =√(1/3), *saptama-karaṇī* =√(1/7), *aṣṭādaśa-karaṇī* =√18, etc.¹ The term was also used in the more general sense of a root. For we have at least one instance of its application in that sense, *e.g.*, *catuṣkaraṇī* =√4, which is not a surd.² The Sanskrit word *karaṇī* means "producer," "that which makes." From that it came to denote the sides of a rectilinear geometrical figure of any shape,³ and then more particularly, the side of a square.