Editing Goniometer (section)

{{Short description|Angle measuring instrument}}
{{Other uses}}
[[File:Goniometer IMG 4841.jpg|thumb|Goniometer made by Develey le Jeune in Lausanne, late 18th–early 19th century]]

A '''goniometer''' is an instrument that either measures an angle or allows an object to be rotated to a precise angular position. The term '''goniometry''' derives from two Greek words, [[Wikt:γωνία|γωνία (''gōnía'')]] '[[angle]]' and [[Wikt:μέτρον#Ancient Greek|μέτρον (''métron'')]] '[[Measurement|measure]]'.<ref>{{cite EB1911 |wstitle=Goniometer |volume=12 |page=234 |first=Leonard James |last=Spencer}}</ref> The '''protractor''' is a commonly used type in the fields of mechanics, engineering, and geometry.

The first known description of a goniometer, based on the [[astrolabe]], was by [[Gemma Frisius]] in 1538.