A polygon has as many angles as it has sides.
There are 32,760 different orders for the first four positions.
This is a permutation where repetition is not allowed; the formula for that is:

For our problem, we have:
Answer: s = -4
Step-by-step explanation:
s/4 + 15 = 14
We can subtract 15 from both sides:
s/4 = -1
We can multiply both sides by 4:
s = -4
Surface area is:
6*8=48
12*10=120
8*12=96
6*12=72
48+72+120+96 = 336
The surface area is 336 square km