Classifying Angles

vertex

A point where two or more straight lines meet.

vertical angles

Angles opposite one another at the intersection of two lines.

adjacent angles

Angles that have a common side and a common vertex (corner point).

congruent angles

Angles that have the same measure

supplementary angles

Angles whose measure adds up to 180 degrees.

complementary angles

Angles whose measure adds up to 90 degrees.

Perpendicular lines

Two lines that intersect at a right angle

obtuse angle

angle that is >90 degrees and <180 degrees.

straight angle

angle that measures exactly 180 degrees.

right angle

angle that measures exactly 90 degrees.

acute angle

angles whose measure is >0 degrees and <90 degrees

linear pair

two angles that are adjacent and supplementary. They form a straight line.