Scheduled maintenance: Thursday, January 26 from 6PM to 7PM PST

acute angle An angle that measures less than 90 degrees.
right angle An angle that measures exactly 90 degrees.
obtuse angle An angle that measures betwwen 90 and 180 degrees.
straight angle An angle that measures exactly 180 degrees.
An angle that measures exactly 180 degrees.
Angles whose measure adds up to 90 degrees.
supplementary angles Angles whose measure adds up to 180 degrees.
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).
vertex A point where two or more straight lines meet.
congruent angles Angles that have the same measure