Final answer:
An acute angle is less than 90 degrees, a right angle is exactly 90 degrees, an obtuse angle is greater than 90 degrees but less than 180 degrees, and a reflex angle is greater than 180 degrees but less than 360 degrees.
Step-by-step explanation:
An acute angle is an angle that measures less than 90 degrees. For example, if you have an angle that measures 60 degrees, it would be considered acute.
A right angle is an angle that measures exactly 90 degrees. It forms a perfect L shape.
An obtuse angle is an angle that measures more than 90 degrees but less than 180 degrees. For example, an angle that measures 120 degrees would be considered obtuse.