Parallel Lines & Transversals - Vocabulary

Vocabulary flashcards covering key terms related to parallel lines, transversals, and angle relationships.

Parallel lines

Two lines in a plane that never intersect; they remain the same distance apart.

Transversal

A line that intersects two or more lines at distinct points.

Corresponding angles

Pairs of angles in matching positions when a transversal crosses two lines; they are congruent if the lines are parallel.

Alternate interior angles

Interior angles on opposite sides of a transversal; they are congruent when the lines are parallel.

Alternate exterior angles

Exterior angles on opposite sides of a transversal; they are congruent when the lines are parallel.

Consecutive interior angles (same-side interior angles)

Interior angles on the same side of the transversal; they are supplementary if the lines are parallel.

Vertical angles

Angles opposite each other when two lines cross; they are always congruent.

Linear pair

Two adjacent angles formed by intersecting lines; they are supplementary.

Congruent

Having equal measure; equal in size.

Supplementary

Two angles whose measures add up to 180 degrees.

Angle

A figure formed by two rays sharing a common endpoint (the vertex).

Degree

Unit of measure for angles; a full circle is 360 degrees.