Parallel Lines and Transversals

Front

What are parallel lines?

Back

Parallel lines are lines in a plane that never meet and are always the same distance apart.

Front

What is a transversal?

Back

A transversal is a line that intersects two or more lines at different points.

Front

What are alternate interior angles?

Back

Alternate interior angles are pairs of angles that are on opposite sides of the transversal and inside the two lines.

Front

What are alternate exterior angles?

Back

Alternate exterior angles are pairs of angles that are on opposite sides of the transversal and outside the two lines.

Front

What are vertical angles?

Back

Vertical angles are the angles opposite each other when two lines intersect. They are always equal.

Front

What are same-side interior angles?

Back

Same-side interior angles are pairs of angles that are on the same side of the transversal and inside the two lines.

Front

What is the relationship between alternate interior angles when the lines are parallel?

Back

When the lines are parallel, alternate interior angles are equal.

Front

What is the relationship between alternate exterior angles when the lines are parallel?

Back

When the lines are parallel, alternate exterior angles are equal.

Front

What is the relationship between same-side interior angles when the lines are parallel?

Back

When the lines are parallel, same-side interior angles are supplementary (add up to 180 degrees).

Front

What is the relationship between vertical angles?

Back

Vertical angles are always equal regardless of whether the lines are parallel or not.