Add all numbers and divide the total by how many numbers there are
24/27 = (24 ÷ 3)/(27 ÷ 3) = 8/9
You have to pick at least one even factor from the set to make an even product.
There are 3 even numbers to choose from, and we can pick up to 3 additional odd numbers.
For example, if we pick out 1 even number and 2 odd numbers, this can be done in

ways. If we pick out 3 even numbers and 0 odd numbers, this can be done in

way.
The total count is then the sum of all possible selections with at least 1 even number and between 0 and 3 odd numbers.

where we use the binomial identity

If the total is 360 degrees then it will take 50 degrees each side. If the total is 180 degrees it would be 30 degrees each side