Why is an hour divided into 60 minutes?
The short answer
Sixty has many divisors and was useful in ancient counting systems, so it became part of the way hours and angles are divided.
How it developed
Dividing an hour into 60 parts makes halves, thirds, and quarters convenient. Modern clocks use new technology, but the unit tradition remains.
A familiar example
Not every time unit is dictated by nature; cultural conventions accumulated over history.