Answer:
must not be
Explanation:
The whole thing equals 360 degrees
Angle B and Angle D are equal; which equals 190 degrees.
Add Angle A to 190 degrees; which is 86 + 190 = 276.
Subtract 360, which is what the whole thing equals, and 276, which is the known angle added together, and you get 56.
In order for this to be a parallelogram, the opposite angles need to be equal.
Since they are not, the answer is must not be.