About Digital Protractor

A protractor measures the opening between two rays that share a vertex. This digital version keeps the baseline fixed at \(0^\circ\) and rotates the other ray so you can read the angle immediately.

• Acute angles are less than \(90^\circ\).
• Right angles are exactly \(90^\circ\).
• Obtuse angles are between \(90^\circ\) and \(180^\circ\).
• The reflex partner of an angle is \(360^\circ - \theta\).