Model Illustrating Finding the Area of a Circle, Ross Surface Form #14
date: label: date made
content: ca 1895
name: label: maker
content: Ross, W. W.
notes: label: Description
content: 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 disc can be arranged as a circle which is divided into six wedges that are hinged together along the perimeter. These may be rearranged to form what the model calls a “rhomboid.”
label: Description
content: One side of the model has four paper stickers and the other has six. One of them reads: AREA OF CIRCLE.
label: Description
content: Ross, like A. H. Kennedy before him, argued that a circle could be considered as the most general case of a polygon with area equal to the sum of the area of triangles, with height equal to the radius of an inscribed circle, and with 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, and the area of a circle half the circumference of the circle times the radius.
label: Description
content: For further information about Ross models, including references, see 1985.0112.190. Closely related models are 1985.0112.200, 1985.0112.201, and 1985.0112.202. Kennedy’s version of this model is 2005.0054.01.
label: Location
content: Currently not on view
place: label: place made
content: United States: Ohio, Fremont
topic: label: Subject
content: Mathematics
setName: label: See more items in
content: Medicine and Science: Mathematics
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content: Science & Mathematics
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content: Arithmetic Teaching
creditLine: label: Credit Line
content: Gift of Wesleyan University
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 1985.0112.203
label: catalog number
content: 1985.0112.203
label: accession number
content: 1985.0112
objectType: label: Object Name
content: geometric model
physicalDescription: label: Physical Description
content: metal (hinges material)
label: Physical Description
content: wood (overall material)
label: Measurements
content: overall: 1 cm x 15 cm x 15 cm; 13/32 in x 5 29/32 in x 5 29/32 in