Via supplementary angles, you can conclude that angle 5 is 60. Because of vertical angles, angle 8 is 120 and angle 7 is 60. Because of alternate exterior angles, angle 1 is congruent to angle 7 and angle 2 is congruent to angle 8, meaning angle 1 is 60 and angle 2 is 120. Because of vertical angles, angle 3 is 60 and angle 4 is 120.
