protractor
Americannoun
-
a person or thing that protracts.
-
(in surveying, mathematics, etc.) an instrument having a graduated arc for plotting or measuring angles.
-
Anatomy. a muscle that causes a part to protrude.
noun
-
an instrument for measuring or drawing angles on paper, usually a flat semicircular transparent plastic sheet graduated in degrees
-
a person or thing that protracts
-
a surgical instrument for removing a bullet from the body
-
anatomy a former term for extensor
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.
Vocabulary lists containing protractor
The Curious Incident of the Dog in the Night-Time
Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!
Geometry - Introductory
Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!
Geometry - Middle School
Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!
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
![]()
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.