Finally, a few protractors in the collections do not obviously belong to any general category, including an object that may not be as old as it appears to be and two instruments that were used by ...

While only one patent model for a protractor survives in the Smithsonian collections—from an inventor with a colorful personal history—several of the other objects also provide examples of technical ...

A protractor is used to draw and measure angles. An angle is the amount of turn between two lines. Angles are measured in degrees with the symbol °. Angles can be labelled with 3 letters (eg DEF ...

You can use a protractor to measure and draw angles. It has a clockwise and an anti-clockwise scale. This is so that you can measure angles to the left or right. Let's have a go at using a ...