Angle Types Explorer

Understanding Straight and Reflex Angles

Definitions

Straight Angle: An angle that measures exactly 180°
Reflex Angle: An angle that measures greater than 180° and less than 360°

Straight Angle ∠XOY

Points X, O, and Y form a straight line

Reflex Angle ∠MON

The reflex angle is the larger arc between rays OM and ON

Interactive Reflex Angle

Drag the slider to explore different reflex angles (181° - 359°)

Key Points to Remember

  • A straight angle always measures exactly 180° and forms a straight line
  • A reflex angle is always the larger angle between two rays (greater than 180°)
  • The sum of a reflex angle and its corresponding acute/obtuse angle is 360°