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protractor

American  
[proh-trak-ter, pruh-] / proʊˈtræk tər, prə- /

noun

protractors plural
  1. a person or thing that protracts.

  2. (in surveying, mathematics, etc.) an instrument having a graduated arc for plotting or measuring angles.

  3. Anatomy. a muscle that causes a part to protrude.


protractor British  
/ prəˈtræktə /

noun

  1. an instrument for measuring or drawing angles on paper, usually a flat semicircular transparent plastic sheet graduated in degrees

  2. a person or thing that protracts

  3. a surgical instrument for removing a bullet from the body

  4. anatomy a former term for extensor

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms

Noun Inflected Forms

Etymology

Origin of protractor

From Medieval Latin, dating back to 1605–15; see origin at protract, -tor

Explanation

A protractor is a device used in drafting and drawing: it's mainly used for drawing and measuring angles. Don't show up to geometry without your protractor! In math class, you use many tools, such as a calculator. Another is the protractor, which is handy when you're studying geometry. Protractors are designed to help you measure and draw angles. You can make a rhombus or an isosceles triangle with a protractor. A protractor can help you measure existing angles too, like if you’re taking a geometry test and need to compare angle measurements. Graphic artists, architects, and other professionals who need to make angles use protractors.

Keep Reading on Vocabulary.com

Vocabulary lists containing protractor

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

The head coach gets a warning, I mean that normally - I don’t know, I didn’t have a protractor out there.

From Washington Times Dec. 11, 2023

Cook admitted he had done his mapping with a protractor and his naked eye, a methodology that seemed to leave Judge Zuniga in disbelief.

From Los Angeles Times Jun. 29, 2021

Study is holding an open book and is surrounded by objects of learning: a lyre, an artist's palette and a protractor.

From BBC Oct. 23, 2020

But where Stella used a protractor to define the curves of his compositions, Gubbiotti seems to look to video games and other computer graphics in devising his hard-edge, multifaceted pictures.

From Washington Post Mar. 8, 2019

The angle of his nose is quantified with a wooden protractor.

From "All the Light We Cannot See" by Anthony Doerr

I learned the ritual that very first summer with my firstborn, when the August air was still heavy but the Target was suddenly full of pens and protractors.

From Salon Aug. 6, 2022

It cannot handle stairs, and the company says it can go up and down slopes that are at a 16 percent incline, so get your protractors out before attempting to take Gita up a ramp.

From The Verge Oct. 15, 2019

A protractor: We don’t get it either, but apparently they all need protractors, because God knows none of us go a single blessed day without finding ourselves in need of a protractor.

From Golf Digest Aug. 10, 2017

It is a tool capable of performing all the tasks protractors, three-section spiral notebooks and No. 2 pencils once performed.

From Washington Times Aug. 13, 2016

These include the earliest dated set of European navigation instruments found thus far: compasses, protractors, calipers, sounding leads, tide calculators, and a device for calculating speed called a log reel.

From "Shipwrecked!" by Martin W. Sandler

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