Ptolemy no doubt deduced this value from his Table of Chords. This gives the lengths of chords of a circle subtended by angles at the centre of AsAd, 1Ad, IF, and so on by hal.f-degrees. The chords are expressed in terms of ... The perimeter of the inscribed regular polygon with 360 sides is 360 times this figure and, dividing by 120 (the number of a#39;parts a#39; in the diameter), we have, as the value of 1r, three times 1 2a#39; 50aquot;, or 3 8a#39; 30aquot;, which is Ptolemya#39;s figure, equivalent to 3-1416. The Indiananbsp;...
|Title||:||A Manual of Greek Mathematics|
|Author||:||Sir Thomas Little Heath|
|Publisher||:||Courier Corporation - 1931|