Set squares are drawing instruments used to create vertical, horizontal, and diagonal lines as well as certain angles. They may be shaped as squares, Ls, or triangles, although in American usage set squares in the form of triangles are typically called "triangles." Sets of drawing instruments often included set squares. A T-square is a similar drafting tool that typically has an edge for holding the instrument in place against a drawing surface. T-squares may be used alone or in combination with set squares.
The squares and triangles in the mathematics collections were made between the 17th and 20th centuries in France, the United States, Japan, and Italy. They were made of brass, steel, aluminum, wood, rubber, and plastic, and they were sometimes marked with scales or combined with other drawing instruments. Draftsmen, surveyors, navigators, military engineers, and architects employed these objects.
The digitization of this group of artifacts was made possible through the generous support of Edward and Diane Straker.