Lots of people ask the same question. Why 360 degrees in a circle? Well it all started with the Babylonians. They used a base of 60, rather then 10 like we do. This system was called the Sexogonal System.
Another reason they used 360, was because 360 is divisible by A LOT of numbers for example 1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 18, 20, 24, 30 and more. The Babylonians calender also was made up of 360 days, when the earth makes a complete rotation, a circle, so to the Babylonians it made sense for a circle to be 360 degrees.
So I hope that my post helped you understand 360. If I missed anything please comment.