Finally figured it out :D
The function rules is:
y = -5x - 1
9 = -5(-2) - 1
4 = -5(-1) - 1
-1 = -5(0) - 1
-6 = -5(1) - 1
-11 = -5(2) - 1
9 hours because 8 x 3 = 24 and 3 x 3 = 9
Gradient of line,m=(17-6)/(20-0)=11/20
finding equation of line using a point (20,17)
y-17=11/20(x-20)
y-17=(11/20x)-11
y=11/20x+(17-11)
y=(11/20)*x+6
L = 14 - 6 = 8
w = 15 - 4 = 11
P of shaded = 2(8+9) = 2 (19) = 38
answer
last one 38ft
