Angle Puzzles & Decomposing Angles

Angles are all around us. Use the protractor to measure, drag a ray to split angles into two parts, and solve puzzles to find the missing angle.

Choose a mode

030609012015018060°
60°Acute
60° is less than 90° — it is an acute angle

Try a preset angle

Angle Reference

Types of Angles

  • Acute: less than 90°
  • Right: exactly 90° (square corner)
  • Obtuse: between 90° and 180°
  • Straight: exactly 180° (flat line)
  • Reflex: more than 180°
  • Full turn: 360°

Angles Are Additive

You can split any angle into smaller parts and add them back up.

  • 30° + 60° = 90° (right angle)
  • 55° + 125° = 180° (straight angle)
  • Angles on a straight line always sum to 180°
  • Angles around a point always sum to 360°