Answer: D!
Step-by-step explanation:
2.

(this is given in the first sentence)
3.

and

due to ...
7. ... the alternate interior angles theorem (which holds because

and

are parallel)
8. Because the above establishes that

, which means

, which in turn means

is a parallelogram.
47 square units is the answer on edge
-1/4 the negative reciprocal of the slope of the red line