Answer:
a=120
b=60
Explanation:
a and 60 are supplementary angles, meaning they add up to 180 degrees.
To find a, subtract 60 from 180 = 120 degrees.
All of the angles within the quadrilateral add up t0 360. Since there are two right angles within, those add to 180. Subtract 180 and 120 from 360 = 60 degrees.