- 1
A protractor is a flat school tool, usually clear plastic, in the shape of a half-circle. You use it to measure an angle in degrees, or to draw an angle of the size you want. The curved edge is marked from 0 to 180. Some are a full circle, marked to 360, but the half-circle is the one most students get. This is classroom English, not a fancy word. Though actually, doctors also use protractor for a muscle that pulls a body part forward — but in school it almost always means the plastic half-circle.
量角器
組成From protract + -or (a thing that protracts, originally that draws out).
同家族的字
- protractthe verb this tool-name is built from
- protractedsame verb, used of something that has been drawn out in time
原始詞典資料5 筆記錄
以下是外部詞典記錄的用法，原文照列，我們還沒有寫成教學內容。上面的說明才是我們自己寫的；有些用法可能上面已經講過了。
protractornoun/pɹəˈtɹæktə(ɹ)/
- 1
One who, or that which, protracts, or causes protraction.
- 2
A circular or semicircular tool for drawing or measuring angles.
- plastic protractor
- measure with a protractor
- 3
medicinesciencessurgeryAn instrument formerly used in extracting foreign or offensive matter from a wound.
- 4
anatomymedicinesciencesA muscle that extends an organ or part; opposed to retractor.
- 5
An adjustable pattern used by tailors.
資料來源：英文維基詞典 English Wiktionary（CC BY-SA 4.0）。 原文照列，未經改寫。