Drafting Triangle

<< >>
This unmarked 5-1/2" wooden right triangle has angles of about 30° and 60°. The corners of the instrument have broken off, and some drawing triangles were neither 30°-60°-90° nor 45°-45°-90°, so it is not possible to know the original dimensions of the object. (For triangles with other angle measurements, see 1990.0690.01 and MA*323412.) Users held the object in place by putting their thumbs in an 11/16" circle cut from the center. Compare to 1979.0876.02, 1983.0238.01, and MA*304826.137.
The dating of other objects from this donor suggests the triangle was made around 1900. The Eugene Dietzgen Company sold a 5-3/4" 30°-60°-90° cherry triangle for 8¢ in 1904, while Keuffel & Esser offered a triangle with the same dimensions but in pearwood for 10¢ in 1909.
References: Catalog of Eugene Dietzgen Co., 7th ed. (Chicago, 1904), 194; Catalogue and Price List of Keuffel & Esser Co., 33rd ed. (New York, 1909), 223.
Currently not on view
date made
ca 1900
Physical Description
wood (overall material)
overall: 7.9 cm x 13.9 cm x .3 cm; 3 1/8 in x 5 15/32 in x 1/8 in
ID Number
catalog number
accession number
Credit Line
Gift of Eunice L. Hoffman
Drawing Instruments
See more items in
Medicine and Science: Mathematics
Science & Mathematics
Squares and Triangles
Data Source
National Museum of American History, Kenneth E. Behring Center


Add a comment about this object