The sum of all of the angles in a parallelogram is 360 degrees. Therefore, there are two of each type of angle in a parallelogram. For example, if one angle was 75 degrees, then one other angle out of the other three would be 75 degrees. This is due to how the angles that are opposite each other in a parallelogram are equal, while those next to each other will form a sum of half of 360 degrees. As a result, you can form an equation that will help you find x, as you already know that the value of another angle is 74 degrees (which is enough information).
