An angle more than 0 degrees and less than 90 degrees.
acute angle
An angle that measures exactly 180 degrees.
straight angle
Angles that are congruent and across from each other.
vertical angles
An angle that measures exactly 90 degrees.
right angle
An angle that measures more than 90 degrees and less than 180 degrees.
obtuse angle
Angles that share a side and are next to each other.
adjacent angles
The sum of two angles equals 180 degrees.
supplementary angles
Two angles add up to 90 degrees.
complementary angles