The domain of a function is
a. the set of all points on the function
b. the set of all first elements of the function
c. the set of all second elements of the function

B. The set of all first elements of the function.

Step-by-step explanation:

We have been given a incomplete sentence. We are asked to complete our given sentence.

We know that the domain of a function is all real values of independent variable for which a function is defined and gives exactly one output.

We know that independent variable is x, which is first element of a point, therefore, the domain of a function is the set of all first elements of the function.

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

the answer

b. they are parallel and will never intersect.