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Angle Calculator

Enter an angle in degrees to see its type, its complement and supplement, and a drawing of it.

How it works Report a problem

Angle Calculator

Interactive visual protractor

About the Angle Calculator

Enter an angle in degrees to see its type, its complement and supplement, and a drawing of it.

How to use the Angle Calculator

  1. Enter the Angle (Degrees) or click a preset such as 30°, 90° or 145°.
  2. Press Draw Angle.

Formula and method

Acute: less than 90°. Right: exactly 90°. Obtuse: between 90° and 180°. Straight: 180°. Reflex: more than 180°. Complement = 90° − θ. Supplement = 180° − θ.

Worked example

A 30° angle is acute, with a complement of 60° and a supplement of 150°. A 145° angle is obtuse.

Tips

  • Angles in a triangle add up to 180°.
  • A full turn is 360°.

Frequently asked questions

What are complementary angles?
Two angles that add up to 90°.