## Measuring Angles with an Instrument

Angles are a fundamental part of geometry and mathematics, and they can be measured using a variety of instruments. The most common instrument used to measure angles is the protractor. A protractor is a semi-circular device that is marked with degrees from 0 to 180 on its curved edge. It is used to measure both acute and obtuse angles.

### Using a Protractor

To use a protractor, first place the center of the protractor at the vertex of the angle you want to measure. Then, line up one side of the angle with the 0 degree mark on the protractor. Finally, read off the degree measurement where the other side of the angle intersects with the curved edge of the protractor. This will give you an accurate measurement of the angle.

### Other Instruments for Measuring Angles

In addition to a protractor, there are several other instruments that can be used to measure angles. These include a goniometer, which is a device that uses two arms connected by a hinge to measure angles; an inclinometer, which measures angles relative to gravity; and an angle finder, which is a tool used for measuring interior and exterior angles in carpentry.