WHY is a circle exactly 360 degrees? In Sumer, and later in Babylon, the decimal number system was used. In this system,
numbers from 1 to 59 were written in the decimal system, then counted in "sixties", then in 3600 (= 60²), and so on. It was then that the circle began to be divided into six times 60 parts, which were later called degrees. But why not just into 60 parts? There are different versions. One explains this choice by the duration of the year (365,25 days), that is,
the sun for a day is moved relative to the stars by about 1 °. According to another version, this division is associated with a regular hexagon inscribed into a circle. Such a construction was found on a cuneiform tablet found in 1936. It was used to estimate the ratio of the length of the circle to its diameter.
