Because the figure is a parallelogram, each opposite angle is equal, so ∡GHJ would be 55° as well. Because there are 360° total, subtract the angle measures you already know (55 x 2) and the remaining two angles have 250° combined. Since they're equal in measure as well, dividing 250 by 2 gives the measure of each of the remaining angles (125°).
You could also just subtract 55 from 180 to get 125°
Ok so we already established that AIA are congruent. So two angles will equal 55 degrees. All angles in a parallelogram add up to 360 degrees, and there are two pairs of matching angles opposite of each other.
So we take the two 55 degree angles and subtract them from 360:
360-110 = 250
Now there are two identical angles left, one of them is x, that equal a total of 250, so divide by two:
