part a
find the value of x.
(1 point)

a. x = 0
b. x = 10
c. x = 20
d. x = 40

part b
find the measure of each labeled angle in the previous question.
(1 point)

a. both of the angles measure 0°.
b. one of the angles measures 50°, and the other angle measures 40°.
c. one of the angles measures 100°, and the other angle measures 80°.
d. one of the angles measures 200°, and the other angle measures 160°.

Alright, Part A. 
This would be 5x + 4x + 5x +4x = 360. This is because all the angles in a parallelogram add up to 360. The other two angles are not unknown, as they correspond with the known angles of 4x and 5x, thus we get all angles.

So add all angles together and we get 18x = 360. We then do x =360/18, thus x = 20. So the answer is C.

Now for the angles, we will have to do the value of the x (which is 20) multiplied by the coefficient (the number in front of the x). So we do 20*4 = 80 and 20*5 = 100. So the answer must be C.