Angles

A line that crosses two parrallel lines is called transversal

Alternate angles are angles that are on opposite sides of the transversal within the parallel lines.

Alternate angles are always equal.

Corresponding angles are angles that are on the same side of the transversal and the parallel lines.

Corresponding angles are also always equal.

Opposite angles are angles that are opposite each other across the intersection of two lines

These are always equal.

Interior angles are angles that are on the same side of the transversal and within the parallel lines.

These add up to 180 degrees.