Part A Complete the sentence below. Select your answers from the drop-down lists.
To find the area of the unshaded region, subtract the area of the
from the sum of
the areas of the
and
Part B
What is the approximate area, in square feet, of the unshaded region? Use the a button on your
calculator and round your answer to the nearest whole foot.
The area of the unshaded region is approximately
square feet.

A little help would be nice

Here is their argument. given the obtuse angle x, we make a quadrilateral abcd with ∠dab = x, and ∠abc = 90◦, and ad = bc. say the perpendicular bisector to dc meets the perpendicular bisector to ab at p. then pa = pb and pc = pd. so the triangles pad and pbc have equal sides and are congruent. thus ∠pad = ∠pbc. but pab is isosceles, hence ∠pab = ∠pba. subtracting, gives x = ∠pad−∠pab = ∠pbc −∠pba = 90◦. this is a preposterous conclusion – just where is the mistake in the "proof" and why does the argument break down there?

What is the measure of x, in degrees

Brook states that the distance on the line is 4 units. caleb states that the whole line does not have a distance because it continues on forever. vivian states that the line is 6 units long. which distance did brook measure? which distance did vivian measure?