Parallel Lines Flashcards

Lines that are always the same distance apart and never meet, no matter how far they are extended.

A line that crosses two or more other lines, which may or may not be parallel.

Angles in matching positions on the same side of the transversal. They are equal when the lines are parallel.

Angles on opposite sides of the transversal but inside the two lines. They are equal when the lines are parallel.

Angles on the same side of the transversal and inside the two lines. They add up to 180° when the lines are parallel.

Angles that are opposite each other when two lines cross. They are always equal.

The sum of the angles in any triangle is always 180°.

The symbol for parallel lines is '∥'. For example, AB ∥ CD means line AB is parallel to line CD.

To prove lines are parallel, show that corresponding angles, alternate angles, or co-interior angles satisfy their respective rules.

Angles on a straight line add up to 180°.