Input value output values (based on the other answers
what's the output of 10 ?)
1 -4

2 -3

3 -2

4 -1

10

  5

Step-by-step explanation:

Increasing the input by 1 seems to increase the output by 1. Increasing the input 6 more from 4 should then increase the output 6 more from -1 to 5.

  (input, output) = (10, 5)

area of part 1:

a1=base*height/2=(8+2)*(8-2-2-1)/2=10*3/2=15 ft^2

area of part 2:

a2=length*width=(8+2)*1=10 ft2

area of part 3:

a3=length*width=8*2=16 ft2

total shaded area : a1+a2+a3=41 ft2

total area of the reactangle : a=16*8=128 ft2

total area of the nonshaded region : 128-41=87 ft2