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Regular Octagon, Ross Surface Form

National Museum of American History

Object Details

Ross, W. W.
Description
This is one of the models of plane figures (surface forms) designed by William Wallace Ross, a school superintendent and mathematics teacher in Fremont, Ohio. The flat wooden object is in the shape of a regular octagon. On the side of the model opposite from the label, an inscribed circle is indicated, as well as four lines joining opposite vertices of the octagon and meeting at the center of the circle. A paper tag attached to the model reads: OCTAGON.
In constructing his visual demonstration of the area of a circle, Ross built several regular polygons, and showed that they had areas equal to the sum of the area of triangles with height equal to the radius of an inscribed circle and sides equal to the sides of the polygons. In other words, the area of the regular polygon equaled half the perimeter of the polygon times the radius of the inscribed circle.
This is the example for an octagon. Compare 1985.0112.200 and 1985.0112.202. For the circle, see 1985.0112.203. For further information about Ross models, including references, see 1985.0112.190.
Location
Currently not on view
Credit Line
Gift of Wesleyan University
ca 1895
ID Number
1985.0112.201
catalog number
1985.0112.201
accession number
1985.0112
Object Name
geometric model
Physical Description
wood (overall material)
Measurements
overall: 1 cm x 14.8 cm x 15 cm; 13/32 in x 5 13/16 in x 5 29/32 in
place made
United States: Ohio, Fremont
See more items in
Medicine and Science: Mathematics
Science & Mathematics
Arithmetic Teaching
National Museum of American History
Subject
Mathematics
Record ID
nmah_694078
Metadata Usage (text)
CC0
GUID (Link to Original Record)
https://n2t.net/ark:/65665/ng49ca746a5-18fd-704b-e053-15f76fa0b4fa

Related Content

  • Arithmetic Teaching Apparatus

    American History Museum
Geometric Model - Ross Surface Form - Octagon, Toward Estimating the Area of a Circle
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International media Interoperability Framework
IIIF provides researchers rich metadata and media viewing options for comparison of works across cultural heritage collections. Visit the IIIF page to learn more.
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