Alternate angles or vertical angles: are those that are on a different side of the secant.
For example ∠1 and ∠2 are vertical angles.
Collateral angles: are those that are on the same side of the secant.
For example ∠1 and ∠2 are collateral angles.
Alternate angles:
Alternate interior angles: are those that are in the interior zone of the parallel lines.
Alternate exterior angles: are those that are in the external zone of the parallel lines.
For example ∠1 and ∠2 are alternate interior angles and ∠3 and ∠4 are alternate exterior angles.
Corresponding angles: are those that on the same side of the secant, one is external and the other internal.
For example ∠1 and ∠2 and ∠3 and ∠4 are corresponding angles.
