Parallel Lines and a Transversal

Front

What are parallel lines?

Back

Parallel lines are lines in a plane that never meet; they 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 corresponding angles?

Back

Corresponding angles are pairs of angles that are in similar positions at each intersection where a transversal crosses two lines.

Front

What is the relationship between corresponding angles when two parallel lines are cut by a transversal?

Back

When two parallel lines are cut by a transversal, corresponding angles are congruent.

Front

What are alternate interior angles?

Back

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

Front

What is the relationship between alternate interior angles when two parallel lines are cut by a transversal?

Back

When two parallel lines are cut by a transversal, alternate interior angles are congruent.

Front

What are consecutive interior angles?

Back

Consecutive interior angles are pairs of angles that lie between the two lines and on the same side of the transversal.

Front

What is the relationship between consecutive interior angles when two parallel lines are cut by a transversal?

Back

When two parallel lines are cut by a transversal, consecutive interior angles are supplementary (they add up to 180 degrees).

Front

What is a linear pair of angles?

Back

A linear pair of angles are two adjacent angles formed when two lines intersect, and they are supplementary.

Front

How do you find the measure of an angle if you know the measures of its corresponding or alternate angles?

Back

You can use the properties of congruent angles to find the measure of an angle by setting it equal to its corresponding or alternate angle.