Answer:
the angle 8
Step-by-step explanation:
this is because when a line crosses parallel lines, then the angles of the crossing line with each of the parallel lines are the same for every line.
FYI, actually there are 2 more congruent angles : 1 and 5.
they are the same as angle 4 due to the "mirroring" effect when you look at the line crossing angles on top and on bottom of a crossed line. and in each side the angles must add up to 180 degrees.
