120 degrees is supplementary to x which makes it 120. 120+120=240 degrees. angle x and angle d = 120+120 which makes it 360 degrees.
M<ADE however, is 110+120=280, 360-280=80 degrees which is 110+120+80=360 degrees. So, M<ADE is 360 degrees and it is equal to M<FDE which is also 360 degrees.
All of them are equal. The sum of the figure is 720 Degrees.