Answer:
a is 30 since it is the same as the angle about it
since we know that that triangle is 90 on one angle 30 on another and the angles add up to 180 we now that b is 60
since a straight like is 180 degrees if we look at c we can see its on a straight line so 180-75=105
a=30
b=60
c=105
Hope This Helps!!!