An acute angle is less than 90°. An obtuse angle is between 90° and 180°. A reflex angle is between 180° and 360°. The size of an angle can be estimated without using a protractor.

An angle is the space between two lines that start at the same point. Angles are measured in degrees (°). They can measure between 0° and 360°. Different types of angles include acute, obtuse ...