How do i figure out prime numbers

You can figure out prime numbers by simply knowing that you can divide that number not more than one. For example, you could know that a prime number is 7 because you can only divide it once like 7 divided by 1. While for number 14, you can divide it twice which isn't a prime number because there is 14 divided by 2 and 14 divided by 1 which is more than one to divide. That's possibly an easy way to understand how to figure them out.

Then, the smallest angle is 2(17) - 1 = 33°