Pronunciation: [pɹətɹˈaktəz] (IPA) 
The word "protractors" is spelled with the IPA phonetic transcription of /prəˈtræktərz/. The first syllable "pro" is pronounced with a schwa /ə/ followed by the consonant cluster /pr/. The next syllable "tract" has the vowel sound of /æ/ and ends with the consonant /t/. The final syllable "ors" has a short vowel sound of /ə/ and ends with the consonant /z/. The word refers to a tool used for measuring angles in geometry.
Protractors are measuring instruments used in geometry and drafting to measure and draw angles accurately. They are typically made of transparent plastic or metal, and consist of a flat, straight base with a central pivot point or hinge that allows the protractor to rotate. The base of a protractor is divided into units of measurement, usually degrees, which are marked along the straight edge.
Protractors are commonly used in mathematics classrooms, engineering, architecture, and other fields that require precise angle measurements. To use a protractor, one aligns the straight edge of the protractor with one side of the angle, making sure the central pivot point is on the vertex (the meeting point of the two sides of the angle). Then, the other side of the angle can be read against the marked units on the base of the protractor, providing the exact measurement in degrees.
Protractors can be divided into two main types: semicircular protractors and full-circle protractors. Semicircular protractors have a 180-degree scale, while full-circle protractors have a 360-degree scale. The 180-degree scale is commonly used for measuring and drawing angles up to 180 degrees, whereas the 360-degree scale allows for the measurement and drawing of angles up to a full circle.
Overall, protractors are indispensable tools for accurately measuring and constructing angles in various practical and academic settings. Their simplicity and effectiveness make them essential for anyone working with angles on a regular basis.
The word "protractors" has its etymology from the Latin word "protrahere". "Protrahere" is a combination of "pro" (forward) and "trahere" (to draw or drag), which means "to draw forward". The term "protractor" was first used in English in the late 16th century to refer to a measuring instrument used for drawing angles.
