What is a protractor?

A protractor is a measuring instrument, typically made of transparent plastic or metal, used for measuring angles in degrees. It is usually shaped as a semicircle or a full circle.

• Semicircular Protractors: These are the most common type. They are marked with a scale from 0 to 180 degrees. To measure an angle, the base of the protractor is aligned with one side of the angle, and the center point of the protractor is placed at the vertex (corner point) of the angle. The degree mark on the protractor where the other side of the angle intersects indicates the angle's measurement.

• Circular Protractors: These protractors are marked with a full 360-degree scale. They offer greater versatility and are useful for measuring reflex angles (angles greater than 180 degrees).

Protractors are used in various fields, including:

• Mathematics: For geometry, trigonometry, and other mathematical calculations.
• Engineering: For designing and constructing structures.
• Navigation: For plotting courses and measuring bearings.
• Drafting: For creating accurate drawings and blueprints.

The accuracy of a protractor depends on the precision of its markings and the user's skill in aligning it correctly. When using a protractor, it is important to ensure the base is properly aligned with one side of the angle and the center point is precisely positioned at the vertex to obtain an accurate measurement.

Angles