Final answer:
Eight angles are formed when a transversal cuts across parallel lines, which can be grouped into different types: corresponding, alternate interior, alternate exterior, and same-side interior angles.
Step-by-step explanation:
When a set of parallel lines are crossed by a transversal, eight angles are formed. These can be categorized into four types: corresponding angles, alternate interior angles, alternate exterior angles, and same-side interior angles. Corresponding angles are those that are in the same relative position at each intersection where the transversal crosses the parallel lines. Alternate interior angles are located between the parallel lines but on opposite sides of the transversal. Alternate exterior angles are located outside the parallel lines but on opposite sides of the transversal. Finally, same-side interior angles are located between the parallel lines on the same side of the transversal.
In summary, four pairs of angles are created when a transversal cuts through parallel lines. These include two pairs of corresponding angles, one pair of alternate interior angles, one pair of alternate exterior angles, and one pair of same-side interior angles. Each pair consists of two equal angles if the lines are indeed parallel.