Types of angles
Acute angle is less than 90° (green).
Right angle is exactly 90° (blue).
Obtuse angle is greater than 90° and less than 180° (brown).
Straight angle is exactly 180° (green).
Reflex angle is greater than 180° and less than 360° (blue).
Full angle is exactly 360° (brown).
And null angle is exactly 0°.
