it's C because the floor area is 120 square feet and the walls are 8 feet so if you multiply 120 × 8 you get 960.
18+30=48
48+40=88
88+40=128
128+50=178
Thats all i found so far in the pattern
30,40,40,50
then it drops
by 140 then adds by 30..
I dont know how else to explain it
Websites similar to Brainly: Quizlet and Socratic
Can I pls have brainliest :(
= 1455
generate a few terms of the sequence using 
= 3n + 2
= ( 3 × 1) + 2 = 5
= (3 × 2) + 2 = 8
= (3 × 3 ) + 2 = 11
= (3 × 4 ) + 2 = 14
= ( 3 × 5 ) + 2 = 17
the terms are 5, 8, 11, 14, 17
these are the terms of an arithmetic sequence
sum to n terms is calculated using 
= 
[ 2a + (n-1)d]
where a is the first term and d the common difference
d = 8 - 5 = 11 - 8 = 14 - 11 = 3 and = 5
= 
[( 2 × 5) + (29 × 3) ]
= 15( 10 + 87) = 15 × 97 = 1455
Regardless of the size of the square, half the diagonal is (√2)/2 times the side of the square.
The ratio is (√2)/2.
_____
Consider a square of side length 1. The Pythagorean theorem tells you the diagonal measure (d) is ...
... d² = 1² +1² = 2
... d = √2
The distance from the center of the square to one of its corners (on the circumscribing circle) is then d/2 = (√2)/2. This is the radius of the circle in which our unit square is inscribed.
Since we're only interested in the ratio of the radius to the side length, using a side length of 1 gets us to that ratio directly.
