What are three devices used to measure an angle?

Answer #1

A protractor helps mostly with measuring angles. A protractor is 180 degress.

Protractors can also be circular and measure up to 360 degrees.

Other methods of measuring angles include using a compasses, and length measuring devices (rulers, tape measures, etc.) used with trigonometry. Estimated angle measures can also use "devices" (a corner of a paper can tell you if an angle is greater than or less than 90 degrees.)

Answer #2

Navigators in the old days would use a sextant for measuring angles. In more recent times they used a transit. A quadrant is another tool for measuring the angle between the horizon and heavenly bodies, useful for navigation.