Date: Wed, 21 Apr 2000 10:21:33 -0400

From: Alex Bogomolny

Thank you for the kind words.

Some history of the sexagesimal notations appears in D.E.Smith, *History of Mathematics*, v2, Dover, 1958. This is a classic book, cheap and immediately available.

Babylonians yet used base 60 notations which is convenient to divide a whole into 2,3,4,...,30 parts. Early Greeks then probably divided the radius of a circle into 60 parts. Hence, the diameter had 120 parts. As Pi was thought to be 3, the circumference was taken to comprise 360 parts.

All the best,

Alexander Bogomolny