What is a transversal?

It is a line that intersects at least two other lines.

This is an example of a transversal.

Notice how the transversal line intersects (or crosses through) two lines.

Corresponding Angles

Corresponding angles are angles that are in the same relative location but in different intersections.

Corresponding?

• #1 DOES show corresponding angles (both are top left of their intersection)

• #2 DOES NOT show corresponding angles (one is top right and the other is bottom left)

• #3 DOES NOT show corresponding angles (one is bottom right and the other is top left)

• #4 DOES show corresponding angles (both are bottom right of their intersection)

Alternate Interior Angles

Angles that are on alternate (or opposite) sides of the transversal and are both INSIDE of the parallel lines are alternate interior angles.

Alternate Exterior Angles

Angles that are on alternate (or opposite) sides of the transversal and are both OUTSIDE of the parallel lines are called alternate exterior angles.

Same Side (Consecutive) Interior Angles

Angles that are both INSIDE of the parallel lines and on the SAME SIDE of the transversal are called same side interior angles.

Same Side (Consecutive) Exterior Angles

Angles that are both OUTSIDE of the parallel lines and on the SAME SIDE of the transversal are called same side exterior angles.

Vertical Angles

Vertical angles are ACROSS from each other at the same intersection. They do not share any common rays.