First, we'll want to write out the equation

then reduce what we can

so this means n can equal any whole number between 9 4/9 & 12, which gives us the options of {10,11}
The answer appears to be choice 3 because it resembles an exponential function.
But I might be wrong.
Hope this helps :)
~ Your Cookie Monster
Answer:
24
Step-by-step explanation:
6.21+6.21=5.7+5.7=23.82
23.82 rounds to 24
(perimeter is all of the sides combined)
561.75 is your answer i hope i helped you get it right