Object Details
- Ross, W. W.
- Description
- This is one of a series of models of plane figures (surface forms) designed by William Wallace Ross, a school superintendent and mathematics teacher in Fremont, Ohio. This example, what Ross called a “trapezium,” is a quadrilateral with four unequal sides, none of them parallel. A diagonal groove joining two opposite vertices, dividing the quadrilateral into two triangles. Ross recommended finding the area of these triangles from the length of their sides.
- A paper sticker attached to the model reads: Trapezium. Another sticker reads: SCALENE TRIANGLE. A second mark on this sticker reads: It is the only operation for which the Ross Blocks have no objective proof or illustration, such objective proof is probably impossible.
- This model is not listed in Ross’s 1891 manual. Here he had written: “The trapezium is measured by dividing it up into triangles. This disposes of all the quadrilaterals.” He apparently revised this view.
- If none of the angles of an arbitrary convex quadrilateral is known, knowing the length of the sides does not suffice to determine the area of the figure.
- Compare models 1985.0112.190 through 1985.0112.202. 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
- 1985.0112.199
- catalog number
- 1985.0112.199
- accession number
- 1985.0112
- Object Name
- geometric model
- Physical Description
- wood (overall material)
- Measurements
- overall: 1 cm x 15.7 cm x 10 cm; 13/32 in x 6 3/16 in x 3 15/16 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_694076
- GUID (Link to Original Record)
- https://n2t.net/ark:/65665/ng49ca746a5-1820-704b-e053-15f76fa0b4fa
