Answer:
(a) a = 60
(b) a = 75
(c) a = 108
All are corresponding.
Explanation:
These questions involve the laws of angles on parallel lines. I like to call them "C", "F" and "Z" angles.
(a) is an example of a "Z" angle. By observation you can see that a is equivalent to the 60 degree angle as they are both internal angles of the "Z" shape created by a line intersecting the pair of parallel lines.
(b) is an example of an "F" angle. a is equivalent to the 75 degree angle because the straight line intersects the pair of parallel lines at the same angle.
(c) is another example of an "F" angle. a is equivalent to the 108 degree angle for the same reason as in question (b).
All the answers are corresponding angles because they are the same as the original. An alternate angle would be where your angle and the original sum to 180, as would be the case in "C" angles (also known as "co-interior" angles).