A semicircular tool for the measurement and construction of angles. On the flat side of the protractor in the middle is either a hole or cross hairs. This is where the vertex (point of the angle) must go when measuring. Usually a horizontal line goes through this point and from one side of the protractor to the other. Sometimes there are no numbers on this line, but 0° or 180° are measured from here. Along the curved part of the protractor there are number markings (also called calibrations), with 90° in the middle. Most protractors have two sets of numbers for each marking so you can measure an angle from either side. One set goes from 0° to 180° — left to right — and the other set goes from 180° to 0°— right to left. A full circle has 360°. When you line up the protractor along one side of an angle, it will be lined up at 0° (on either the inner or outer set of numbers). This will tell you which set of numbers to read.

Glossary of Art Terms. 2014.

Игры ⚽ Поможем решить контрольную работу

Look at other dictionaries:

  • Protractor — Pro*tract or, n. 1. One who, or that which, protracts, or causes protraction. [1913 Webster] 2. A mathematical instrument for laying down and measuring angles on paper, used in drawing or in plotting. It is of various forms, semicircular,… …   The Collaborative International Dictionary of English

  • protractor — PROTRACTÓR, OÁRE adj., s. m. (muşchi) care are rolul de a întinde un membru sau o parte a corpului spre înainte. (< fr. protracteur) Trimis de raduborza, 15.09.2007. Sursa: MDN …   Dicționar Român

  • protractor — 1610s, one who lengthens (an action), agent noun from L. protrahere (see PROTRACT (Cf. protract)); sense of instrument for drawing angles first recorded 1650s …   Etymology dictionary

  • protractor — the instrument used in geometry, is spelt or, not er …   Modern English usage

  • protractor — ► NOUN ▪ an instrument for measuring angles, typically in the form of a flat semicircle marked with degrees along the curved edge …   English terms dictionary

  • protractor — [prō′trak΄tər, prō trak′tər] n. [ML] 1. a person or thing that protracts 2. an instrument in the form of a graduated semicircle, used for plotting and measuring angles 3. Anat. a muscle that protracts, or extends, a limb …   English World dictionary

  • Protractor — In geometry, a protractor is a circular or semicircular tool for measuring an angle or a circle. The units of measurement utilized are usually degrees.Some protractors are simple half discs; these have existed since ancient times. More advanced… …   Wikipedia

  • protractor — /proh trak teuhr, preuh /, n. 1. a person or thing that protracts. 2. (in surveying, mathematics, etc.) an instrument having a graduated arc for plotting or measuring angles. 3. Anat. a muscle that causes a part to protrude. [1605 15; < ML; see… …   Universalium

  • protractor — matlankis statusas T sritis Standartizacija ir metrologija apibrėžtis Įtaisas kampams matuoti ir žymėti brėžinyje. atitikmenys: angl. angle protractor; protractor; semicircular protractor vok. Winkelmesser, n rus. транспортир, m pranc. demi… …   Penkiakalbis aiškinamasis metrologijos terminų žodynas

  • protractor — matlankis statusas T sritis fizika atitikmenys: angl. angle protractor; protractor; semicircular protractor vok. Transporteur, m; Winkelmesser, n rus. транспортир, m pranc. demi cercle gradué, m; rapporteur, m …   Fizikos terminų žodynas

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”