Unit 2A - Parallel lines

Angles, Parallel line & Intro to Proofs

Adjacent angles

two angles in the same plane that share a vertex and a ray but share no common interior points (cannot overlap)

Complementary angles

two angles with measures that have a sum of 90 degrees. angles may be adjacent or non-adjacent

Supplementary angles

two angles with measures that have a sum of 180 degrees. angles may be adjacent or non-adjacent

Linear pair

two adjacent angles with non-common sides that are opposite rays. two angles that form a linear pair are supplementary

Angle addition postulate

two adjacent angles form a whole angle. the measure of the whole angle equals the sum of the measurements of the two adjacent angles

Vertical angles

two opposite angles formed by two intersecting lines

Vertical angles theorem

vertical angles are congruent

Transversal

a line that intersects two or more lines in different points

Corresponding angles

non-adjacent angles that lie on the same side of the transversal, one exterior and one interior

Alternate interior angles

non-adjacent interior angles that lie on opposite sides of the transversal

Alternate exterior angles

non-adjacent exterior angles that lie on opposite sides of a transversal

Consecutive interior angles

non-adjacent interior angles that lie on the same side of the transversal