Angles and Angle Relationship Vocabulary

Right Angle

an angle that measures exactly 90 degrees.

Vertex

a point where two or more rays meet; the "corner" of an angle

Vertical Angles

two angles opposite one another at the intersection of two lines

Adjacent Angles

angles that have a common side and a common vertex (corner point)

Linear Pair

a pair of adjacent angles that make a straight angle (have a supplementary relationship)

Complementary Angles

two angles whose measure adds up to 90 degrees

Supplementary Angles

two angles whose measure adds up to 180 degrees

Congruent Angles

Angles that have the same measure

Straight Angle

An angle whose measure is exactly 180 degrees

Acute Angle

An angle that measures more than 0 degrees but less than 90 degrees

Obtuse Angle

An angle that measures more than 90 degrees but less than 180 degrees

Angle Sides

the two rays forming an angle

Angle Bisector

a ray that divides an angle into two congruent angles

Angle Addition Postulate

if point B lies in the interior of

congruent angles

angles that have the same measure