Answers are
a = 108
b = 72
c = 55
d = 125
Step by step
We use straight angle = 180 degrees to determine the unknown angle between 55* and 72*. 180 - 72 - 55 = 53 degrees.
Now we can fill in the vertical angles for each of these known angles. Vertical angles are opposite angles and have the same angle degree so fill those in.
Next we notice two parallel lines bisected two times. I highlighted the interior of those parallel lines and marked the two bisections with red and green.
Red bisector gives us the known 72 degree angle is congruent with its opposite interior angle so (b) is 72. Since it sits on a straight angle we can take 180 and subtract 72 = 108 degrees for (a)
Green bisector gives us the known 55 degree angle is congruent with its opposite interior angle so (c) is 55. Since it sits on a straight angle we can take 180 and subtract 55 = 125 degrees for (d)
Problem solved! See attachment it might help