Hi there!
The angle measure of 3 is 140 degrees.
4 and 3 may not be in congruent spots but 4 and 2 are. Remember two of these angles next to each other equal 180 degrees. If 2 is also 40 degrees than 180 - 40 = 140. Alternate angles are equal meaning 3 is 140 degrees.
Hope this helps !