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Raoul Bricard (23 March 1870 – 26 November 1943) was a French engineer and a mathematician. He is best known for his work in geometry, especially descriptive geometry and scissors congruence, and kinematics, especially mechanical linkages.

Raoul Bricard
Born(1870-03-23)23 March 1870
Died26 November 1943(1943-11-26) (aged 73)
Scientific career
FieldsMathematics

Biography

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Bricard taught geometry at Ecole Centrale des Arts et Manufactures. In 1908 he became a professor of applied geometry at the National Conservatory of Arts and Crafts in Paris.[1] In 1932 he received the Poncelet Prize in mathematics from the Paris Academy of Sciences for his work in geometry.[2]

Work

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In 1896 Bricard published a paper on Hilbert's third problem, even before the problem was stated by Hilbert.[3] In it he proved that mirror symmetric polytopes are scissors congruent, and proved a weak version of Dehn's criterion.

 
One of the Bricard octahedra

In 1897 Bricard published an important investigation on flexible polyhedra.[4] In it he classified all flexible octahedra, now known as Bricard octahedra.[5] This work was the subject of Henri Lebesgue's lectures in 1938.[6] Later Bricard discovered notable 6-bar linkages.[7][8]

Bricard also gave one of the first geometric proofs of Morley's trisector theorem in 1922.[9][10]

Books

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Bricard authored six books, including a mathematics survey in Esperanto.[11] He is listed in Encyclopedia of Esperanto.[12]

Notes

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  1. ^ Science, vol. 28 (1908), p. 707.
  2. ^ "Prize Awards of the Paris Academy of Sciences", Nature vol. 131 (1933) 174-175.
  3. ^ R. Bricard, "Sur une question de géométrie relative aux polyèdres", Nouvelles annales de mathématiques, Ser. 3, Vol. 15 (1896), 331-334.
  4. ^ R. Bricard, Mémoire sur la théorie de l’octaèdre articulé Archived 2011-07-17 at the Wayback Machine, J. Math. Pures Appl., Vol. 3 (1897), 113–150 (see also the English translation and an alternative scan).
  5. ^ P. Cromwell, Polyhedra, Cambridge University Press, 1997.
  6. ^ Lebesgue H. (1967). "Octaedres articules de Bricard". Enseign. Math. Series 2. 13 (3): 175–185. doi:10.5169/seals-41541.
  7. ^ K. Wohlhart, The two types of the orthogonal Bricard linkage, Mechanism and machine theory, vol. 28 (1993), 809-817.
  8. ^ Bricard 6 Bar Linkage Origami on YouTube.
  9. ^ Guy Richard K. (2007). "The Lighthouse Theorem, Morley & Malfatti - A Budget of Paradoxes" (PDF). American Mathematical Monthly. 114 (2): 97–141. doi:10.1080/00029890.2007.11920398. JSTOR 27642143. S2CID 46275242. Archived from the original (PDF) on April 19, 2012.
  10. ^ Alain Connes, "Symmetries", European Mathematical Society Newsletter No. 54 (December 2004).
  11. ^ Raoul Bricard, from Open Library.
  12. ^ Encyclopedia of Esperanto Archived 2008-12-18 at the Wayback Machine
  13. ^ Emch, Arnold (1925). "Review: Petit Traité de Perspective by Raoul Bricard" (PDF). Bull. Amer. Math. Soc. 31 (9): 564–565. doi:10.1090/s0002-9904-1925-04125-7.

References

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  • Laurent R., Raoul Bricard, Professeur de Géométrie appliquée aux arts, in Fontanon C., Grelon A. (éds.), Les professeurs du Conservatoire national des arts et métiers, dictionnaire biographique, 1794-1955, INRP-CNAM, Paris 1994, vol. 1, pp. 286–291.
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