Answer: 140
Explanation:
Angle 4 and A are supplementary meaning they add to 180
Thus you can do 180-40 = 140 to get that angle A = 140.
Since the two lines are parallel, Angle A is congruent to Angle D. Then, since Angle D is opposite Angle 3, we know that that Angle 3 and Angle D are congruent.