Angle: An Illustrated Classification

The applet below illustrates the common classification of angles based an their angular measure. The applet illustrates both regular and signed angle types.

For unsigned angles,

  • An angle is zero if its two sides coincide and its interior is empty.
  • An angle is full if its two sides coincide and its interior is the whole plane with a ray removed.
  • An angle is straight if its two sides form a straight line. Either of the so formed half-planes may be the interior of the angle.
  • An angle is right if when doubled it makes one straight angle.
  • An angle less than right is acute.
  • An angle less than straight but greater than right is obtuse.
  • An angle between straight and full is reflex.

Created with GeoGebra

Related material
Read more...

  • What Is Angle?
  • Demagoguery: An Attempt at Classification
  • What Is Elementary Mathematics?
  • Classification of Quadrilaterals
  • Triangle Classification
  • |Activities| |Contact| |Front page| |Contents| |Geometry| |Store|

    Copyright © 1996-2017 Alexander Bogomolny

     62351875

    Search by google: