When two parallel lines are cut by a transversal, the pairs of angles that are on the same side of the transversal (one inside the parallel lines and one outside the parallel lines) and are congruent

Two angles in the same relative position on two lines when those lines are cut by a transversal.

Two angles in corresponding positions relative to two lines.

Angles which lie on the same side of a transversal.

Angles in the same position from one line to another.

Angles that have the same relative positions.

1 and 2 and 3 and 4 and 8 are pairs of corresponding angles in the figure at right(Lesson 4.2).

Any pair of angles on the same side of the transversal, one interior and one exterior, formed when two parallel lines are intersected by a transversal.