protractor

IPA/prəˈtræktə(r)/
IPA/prəˈtræktər/

protractor — noun

  • protractorsingular
  • protractorsplural

1. A flat tool, usually a clear half circle marked with degrees, that helps you mea

1.名詞B1
釋義

A flat tool, usually a clear half circle marked with degrees, that helps you measure an angle or draw one accurately.

例句

Yumi used a protractor to check whether the roof angle was exactly 45 degrees.

use a protractor to check an angle

The art teacher told Pedro to draw the triangle again with a protractor.

同義詞
  • angle finder

    a broader tool for checking or copying angles, often used in building or DIY work rather than school geometry

  • set square

    a triangular drawing tool for fixed angles such as 45° or 90°, unlike a protractor which can measure many different angles

  • ruler

    used for measuring length and drawing straight lines, not for reading the size of an angle

文法句型

use + a protractor + to-infinitive

measure + angle + with + a protractor

用法筆記

Usually used with verbs such as 'use', 'place', 'line up', and 'measure'. In school instructions, it often refers to checking the size of an angle or drawing a new one from a point on the page.

常見錯誤

❌Use a ruler to measure the angle.
✅Use a protractor to measure the angle.
💡A ruler measures length, but a protractor is the tool for reading angles.