### Why 360?

Sunday, October 4, 2009
Why do we use the number 360 when we refer to a circle, why not 400 or 10?
Well I did some research and found out it was the Babylonians!! The Babylonians used a system called the sexagesimal system, so instead of using the base of 10, like we do they used a base of 60.

This has many advantages as it can be divided by a lot of factors unlike 10. The base of 10 only has factors of (1,2,5,10) but 360 has factors of 1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 18, 20, 24, 30, 36, 40, 45, 60, 72, 90, 120, 180, and 360. So you now know why we use 360 degrees for a circle, but there is also other examples, like we have 60 minutes in an hour, and 60 seconds in a minute. But the most common example is the calendar. Earth's rotation around the earth is approximately 360 days (rotation over the sun)

The Babylonians had 360 days in a year, but in the present we now have 365 days (more accurate). Thats why every few hundred years, summer would line up to winter, meaning the calendar would be all messed up.
I hope you learned something and please comment!!