protractor

A protractor is a measuring tool used to determine angles, typically in degrees. It is usually semi-circular or circular with marked gradations, allowing precise measurement of angles between two lines or surfaces. You place the baseline of the protractor along one side of the angle, align the center point with the vertex (where the two lines meet), and then read the degree measurement where the other side intersects the scale. Protractors are essential in fields like drafting, engineering, and architecture for creating or analyzing accurate angles in designs and constructions.