Angle Relationships with 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 alternate interior angles?

Back

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

Front

What are vertical angles?

Back

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

Front

What is a linear pair of angles?

Back

A linear pair of angles are two adjacent angles that form a straight line. They are supplementary.

Front

What are same-side interior angles?

Back

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

Front

What are corresponding angles?

Back

Corresponding angles are pairs of angles that are in the same position at each intersection where a transversal crosses two lines.

Front

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

Back

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

Front

What is the relationship between vertical angles?

Back

Vertical angles are always equal regardless of the position of the intersecting lines.

Front

What is the relationship between linear pairs of angles?

Back

Linear pairs of angles are supplementary, meaning their measures add up to 180 degrees.