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Sixteen-Sided Regular Polygon, Ross Surface Form

American History Museum

Geometric Model - Ross Surface Form - 16-Sided Polygon, Toward Estimating the Area of a Circle
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  • Geometric Model - Ross Surface Form - 16-Sided Polygon, Toward Estimating the Area of a Circle
  • Geometric Model - Ross Surface Form - 16-Sided Polygon, Toward Estimating the Area of a Circle
  • Geometric Models - Ross Surface Forms and Solids
  • Geometric Models - Ross Surface Forms and Solids

    Object Details

    maker

    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 unpainted wooden object is in the shape of a regular polygon with sixteen sides. On the opposite side from the paper label, it has eight straight lines drawn joining opposite vertices, dividing the polygon into 16 equal triangles. The lines meet at a point. The label reads: POLYGON OF 16 SIDES.
    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 a 16-sided figure. Compare 1985.0112.200 and 1985.0112.201. 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

    date made

    ca 1895

    ID Number

    1985.0112.202

    catalog number

    1985.0112.202

    accession number

    1985.0112

    Object Name

    geometric model

    Physical Description

    wood (overall material)

    Measurements

    overall: 1 cm x 15 cm x 15 cm; 13/32 in x 5 29/32 in x 5 29/32 in

    place made

    United States: Ohio, Fremont

    See more items in

    Medicine and Science: Mathematics
    Science & Mathematics
    Arithmetic Teaching

    Data Source

    National Museum of American History

    Subject

    Mathematics

    Metadata Usage

    CC0

    Link to Original Record

    https://n2t.net/ark:/65665/ng49ca746a5-1900-704b-e053-15f76fa0b4fa

    Record ID

    nmah_694079

    Discover More

    Dissected wooden sphere laid flat, taking the form of an 8-pointed star.

    Geometrical Models for Arithmetic Teaching

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