First we need the distances of the sides of the polygon, because perimeter = sum of all sides.






Now, we add all sides for the perimeter:
p = d1 + d2 + d3 + d4 + d5
p = 3+5+5+3+4 = 20 units
For 5 cameras if you just divide 27 divide by 2 that per camera which is $13.50 then you add $105 to $13.50 and you get $118.50
Step-by-step explanation:

So sqrt(40) lies between 6 and 7.
Supplementary because the line equals 180°
(x-21)+x
2x-21=180
2x=201
×=100.5°