Keep the construction lines when you draw them as they are evidence that you have constructed the triangle correctly.

Use a ruler, protractor and a pair of compasses to construct a triangle accurately. After the triangle has been constructed, leave the construction lines visible so each stage of the process is shown ...

Besides measuring angles, the protractor may be used to open the rectangular pieces to a desired angle. Then, an angle or triangle may be drawn along the inside edges, which are marked with a ...

IIIF provides researchers rich metadata and media viewing options for comparison of works across cultural heritage collections. Visit the IIIF page to learn more. See also ID number 1977.0460.01.