18+12*4=18+48=66 ft
1st floor is 18ft
next 4 are 12ft
I believe it's Line y=-x+2 and y=3x+1 intersect the y-axis. From what I've gathered, they are parallel lines, and both are set on the y-axis.
This is probably way overcomplicated but i cant remember how to do it
w = n
l = 2n+1
w*l = 66
n(2n+1) = 66
2n^2 + n =66
2n^2 + n - 66 = 0
using quadratic equation
n = 11/2
width = 11/2 = 5.5
length = 11 + 1 = 12