since quarantine my brain seems to be forgetting things.
what's the formula of area of a polygon
(I think is something like 1/2 AP but i cant remember what the A and P stand for, and idk if that's even right)

Step-by-step explanation:

for the area of a regular polygon, the formula is area=1/2 perimeter x apothem, or area=1/2pa

the apothem(A) is the segment that joins the center to the midpoint of any side

Option 'C' is correct.

Step-by-step explanation:

Since we have given that

We need to solve this:

Simplify the brackets:

So, required equation would be

Hence, Option 'C' is correct.