What is the equation of the horizontal line that passes through ( 2 -2 )

  y = -2

Step-by-step explanation:

The equation of a horizontal line is ...

  y = constant

In order to make it go through a point with a y-coordinate of -2, the value of the constant must be -2.

Your line is y = -2.

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