Indian Mathematics c6.11

c6.11

We thus have three distinct stages :
(a) The chords of Ptolemy, or ch'd α , with r = 60
(b) The Pauliśa sine or sin (α)/2 = (ch'd α)/2, with r = 120
(c) The Āryabhata sine or sin (α)/2 = 3/(π) · (ch'd α)/2 with r = 3438' To obtain (c) the value of π actually used was 600/191 (= 3.14136)