History of Technology in India, Vol. I: From Antiquity to c. 1200 A.D. v1.c38.s1.t2.12

For, cube of one muṣṭi aṅg and parva aṅg changed into sphere, the radius becomes: (1 muṣṭi aṅg)³ = (4.16 cms)³ = 4/3π r₁³.