Parallel Lines and Transversals

Front

What are parallel lines?

Back

Parallel lines are lines in a plane that never meet or intersect. They are always the same distance apart.

Front

What is a transversal?

Back

A transversal is a line that crosses at least two other lines in the same plane.

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 are supplementary angles?

Back

Supplementary angles are two angles whose measures add up to 180 degrees.

Front

What are vertical angles?

Back

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

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

If two parallel lines are cut by a transversal, what can be said about the corresponding angles?

Back

Corresponding angles are equal when two parallel lines are cut by a transversal.

Front

If two parallel lines are cut by a transversal, what can be said about the alternate interior angles?

Back

Alternate interior angles are equal when two parallel lines are cut by a transversal.

Front

If two angles are supplementary, what is the sum of their measures?

Back

The sum of the measures of supplementary angles is 180 degrees.