Parallel Lines and Angle Theorems

Vocabulary flashcards covering the definitions, theorems, and mnemonics related to parallel lines and transversals.

Parallel lines

Straight lines that are the same distance from each other along the whole of their length and will never meet or intersect.

Transversal

A straight line that intersects parallel lines, creating angles with distinct geometric properties.

Alternate angles

A pair of angles formed on opposite sides of a transversal between parallel lines that are equal in measure.

Corresponding angles

Angles located on the same side of the transversal that both lie either above or below the parallel lines and are equal in measure.

Supplementary

A term describing two or more angles whose sum is equal to $180^\circ$.

Co-interior angles

Interior angles lying on the same side of a transversal between parallel lines that add up to $180^\circ$ (are supplementary).

F (FUN acronym)

The letter shape used to easily identify corresponding angles formed between parallel lines and a transversal.

U (FUN acronym)

The letter shape used to easily identify co-interior angles, which add up to $180^\circ$.

N (FUN acronym)

The letter shape used to easily identify alternate angles, which are equal when lines are parallel.