Open Triangle

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This 8" 30°-60°-90° triangle with an open interior is made of two different kinds of mahogany, with a section of reddish wood set between two sections of darker wood. A small triangle is etched in the short leg. On the back, the object has a sticker marked: 839. Compare to 335329, 335330, and 1977.1101.89.
James W. Queen of Philadelphia sold a similar ebony or maple triangle with a mahogany inlay, but not in an 8" size. The previous owner of this instrument collected more than 1,200 hand tools and machine tools and displayed them at his family's building company in Baltimore, Md. This object was item number 839 in his collection.
Reference: James W. Queen & Co., Priced and Illustrated Catalogue of Mathematical Instruments (Philadelphia, 1883), 51.
Currently not on view
date made
ca 1900
Physical Description
mahogany (overall material)
overall: 20.4 cm x 11.8 cm x .3 cm; 8 1/32 in x 4 21/32 in x 1/8 in
ID Number
catalog number
accession number
Credit Line
The John R. Gerwig, Jr., Collection
Drawing Instruments
See more items in
Medicine and Science: Mathematics
Science & Mathematics
Squares and Triangles
Data Source
National Museum of American History


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