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.
Copyright © 1996-2018 Alexander Bogomolny