Protractors

Part of speech: noun

Definitions

1. Instruments used for measuring angles accurately, often semi-circular with degree markings ; tools for drawing or constructing precise angles in geometry or engineering ; devices designed to determine angular measurement between two intersecting lines or surfaces
2. Devices shaped typically in a semi-circle or circular form with marked degrees used for gauging angles ; precision tools employed in mathematics and drafting to measure angles ; apparatus designed to aid in drawing or assessing the size of angles in various contexts
3. Tools commonly made of transparent plastic or metal, marked with degrees in a half-circle or full circle to assess angles ; used by students and professionals to measure or create angles ; geometric instruments that allow the accurate determination or construction of angular measures

Etymology: The protractor is named for what it does: it draws out, or extends, a line. Its ancestor is the Latin verb "protrahere", built from "pro-", forward, and "trahere", to draw or drag, the same root that gives English "tractor" and "traction". Latin "protractus" was the past participle of this verb, meaning "drawn forward" or "prolonged", and English "protract" came from that stem with the sense of lengthening something in time or space. The tool itself takes its name from the agent suffix "-or", which English attaches to verbs to name a thing that performs an action. A protractor, then, is literally a thing that protracts: an instrument for extending a line out from a point so that an angle can be read against a scale. The plural "protractors" simply names more than one such instrument.

Synonyms: angle measurers, measuring tools, instruments, geometry tools, drafting tools