## 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°.