Parallel Lines & Transversals - Angle Relationships

Front

What are parallel lines?

Back

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

Front

What is a transversal?

Back

A transversal is a line that crosses at least two other lines. When it intersects parallel lines, it creates several angles.

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. They are equal in measure.

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. They are equal in measure when the lines are parallel.

Front

What are consecutive interior angles?

Back

Consecutive interior angles are pairs of angles that lie between two lines on the same side of a transversal. They are supplementary when the lines are parallel.

Front

What are vertical angles?

Back

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

Front

What is the sum of angles on a straight line?

Back

The sum of angles on a straight line is 180°.

Front

What is the sum of angles around a point?

Back

The sum of angles around a point is 360°.

Front

If angle 1 is 70°, what is the measure of angle 2 if they are corresponding angles?

Back

Angle 2 is also 70° because corresponding angles are equal.

Front

If angle 3 is 120°, what is the measure of angle 4 if they are alternate interior angles?

Back

Angle 4 is also 120° because alternate interior angles are equal.