What is a tool used to mesure angles?

Unit of Measure

- Angles are measured in degrees or radians. A degree represents 1/360 of a circle. Each degree is subdivided into 60 minutes. And each minute has 60 seconds. The basic tools used to measure angles are a protractor, compass and set square.

Protractor

- The protractor is a semi-circular instrument with the degrees marked from 0 to 180. There are two sets of markings; the inner scale goes from right to left and the outer scale from left to right.

Compass

- A compass is a hinged set of arms. One arm has a pointed end and the other holds a pencil. The compass is used to measure and construct angles.

Set Square and Sextant

- Set squares are of two kinds--the 90-45-45 degree angle and the 30-60-90 degree angle. They are measuring tools used in drafting and engineering. A sextant is an ancient navigating tool.