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Varignon
Pierre Varignon (; 1654 – 23 December 1722) was a French mathematician. He was educated at the Society of Jesus, Jesuit College and the University of Caen, where he received his Magister Artium, M.A. in 1682. He took Holy Orders the following year. Varignon gained his first exposure to mathematics by reading Euclid and then René Descartes, Descartes' ''La Géométrie''. He became professor of mathematics at the Collège des Quatre-Nations, Collège Mazarin in Paris in 1688 and was elected to the Académie Royale des Sciences in the same year. In 1704, he held the departmental chair at Collège Mazarin and also became professor of mathematics at the Collège de France, Collège Royal. He was elected to the Prussian Academy of Sciences, Berlin Academy in 1713 and to the Royal Society in 1718. Many of his works were published in Paris in 1725, three years after his death. His lectures at Mazarin were published in Elements de mathematique' in 1731. Varignon was a friend of Isaa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Varignon's Theorem
In Euclidean geometry, Varignon's theorem holds that the midpoints of the sides of an arbitrary quadrilateral form a parallelogram, called the Varignon parallelogram. It is named after Pierre Varignon, whose proof was published posthumously in 1731. Theorem The midpoints of the sides of an arbitrary quadrilateral form a parallelogram. If the quadrilateral is convex or concave (not complex), then the area of the parallelogram is half the area of the quadrilateral. If one introduces the concept of oriented areas for ''n''-gons, then this area equality also holds for complex quadrilaterals. Coxeter, H. S. M. and Greitzer, S. L. "Quadrangle; Varignon's theorem" §3.1 in Geometry Revisited. Washington, DC: Math. Assoc. Amer., pp. 52–54, 1967. The Varignon parallelogram exists even for a skew quadrilateral, and is planar whether the quadrilateral is planar or not. The theorem can be generalized to the midpoint polygon of an arbitrary polygon. Proof Referring to the diag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |