Angle 4 would be 77degrees because angle two is vertical to angle four.
Angle 3 and Angle 1 are equal because they are vertical to each other.
You would subtract 180 (degrees) minus 77 (degrees) and get 103 (degrees).
So Angle 3 and Angle 1 would both be 103 degrees.
You would get 180 degrees from the line.