Angle Relationships

Front

Transversal

Back

A line that passes across two or more other lines in the same plane.

Front

Parallel lines

Back

Lines in a plane that do not meet; they are always the same distance apart.

Front

Perpendicular lines

Back

Lines that intersect at a right angle (90 degrees).

Front

Right angle

Back

An angle of 90 degrees.

Front

Vertical angles

Back

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

Front

Supplementary angles

Back

Two angles whose measures add up to 180 degrees.

Front

Linear pair

Back

A pair of adjacent angles formed when two lines intersect. The angles are supplementary.

Front

Complementary angles

Back

Two angles whose measures add up to 90 degrees.

Front

Same side interior angles

Back

Angles on the same side of the transversal and inside the two lines. They are supplementary if the lines are parallel.

Front

Same side exterior angles

Back

Angles on the same side of the transversal and outside the two lines. They are supplementary if the lines are parallel.