Hello!!
Well, the angles in a triangle must add up to 180 degrees.
So, since one angle is 40 degrees, the other two angles must add up to 140 degrees.
A quick look over the answer choices will show that option C, 35 degrees and 105 degrees, is the only possible answer.
Hope this helps!! Let me know if you have ANY questions.
Angle AGD is a right angle which equals 90 degrees.
Angle FGD would be 90-73 = 17 degrees.
Angle X is a vertical angle to FGD, which means they are the same.
Angle X = 17 degrees.