Final answer:
When two parallel lines are cut by a transversal, corresponding angles are equal and occupy the same relative position; any pairs that don't follow this are not corresponding angles.
Step-by-step explanation:
To determine which set of angle pairs are NOT corresponding angles when two parallel lines are cut by a transversal, we must first understand what corresponding angles are. Corresponding angles are those that occupy the same relative position at each intersection where the transversal cuts the parallel lines.
They are equal in measure if the lines are parallel. In the scenario described, the corresponding angles would be: (1 and 5), (2 and 6), (3 and 7), (4 and 8). Thus, any other combination of angles, such as (1 and 6), (2 and 7), (3 and 8), or (4 and 5), would not be considered corresponding angles.