The number of degrees in a circle is 360. Haven't you guys ever wondered why? Well the answer to that dates back to a long time ago. About the time of the Babylonians. It's a somewhat complicated method, but it will be explained simpler in this post. This is only one of the explanations, as there is many more out there. Have a look at other posts for different theories.
Anyways, the Babylonians were very smart people. They had and used a sexagesimal numeral system. They used 60 as their base number, whereas we use 10. The Babylonians were smart enough to figure out that 360 was close enough to a full year. They were only 5.25 days off. Now here's where it gets a bit complicated. They knew the sun went around the earth in a circle (it doesn't, it goes around in an eclipse [oval shape]) and they knew it takes 360 days for that to happen. All they had to do now, was put those 2 together. You have a circle, and you have 360 days to complete it, make sense? Look at this picture to the right, imagine each day being 1 degree. The sun goes around moves around the earth about 1 degree per day. When I read that, I understood why the number 360 was used.
Why not 360? 360 is a great number. Did you know it has an astonishing 24 factors? Imagine if you used the number 100 for a circle. The only factors you would have there are 1, 2, 4, 5, 10, 20, 25, 50, and 100. Now let's look at the number 360. I'll list them all, but be prepared for a mouthful of numbers. The factors are, 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. Talk about a great number. That's all that there is too it. It's one of the many theories of why 360 was chosen. And why not? Hope this post helps a bunch, be sure to comment and tell me if I missed anything or if I helped you out.