Measuring angles

Math

Definition

The process of determining the size of an angle using a protractor, measured in degrees. Angles are classified by their measure: acute (< 90°), right (= 90°), obtuse (> 90° and < 180°), and straight (= 180°).

Examples

  • Using a protractor to measure a 45° angle
  • Identifying a 120° angle as obtuse
  • A straight line forms a 180° angle

Related Terms

Angle pairs Degree to radian conversion Coterminal angles

Study This Concept

Practice measuring angles with free review games in these units:

Geometry Unit 1: Points Lines and Planes