Supplementary angles are two angles that add up to 180°. 180÷3=60. 60*2=120. 120+60=160.
m∠A=60° and m∠B=120°.
This question is talking about vertical angles. One of the angles is 127°, so the one opposite to it is also 127° (look up vertical angles if you don't understand).
I don't know how to find the other two angles though.