• Thumbnail for Oval (projective plane)
    necessarily embedded in a projective plane. Indeed, there exist abstract ovals which can not lie in any projective plane. In a projective plane a set Ω of points...
    33 KB (4,186 words) - 06:38, 23 April 2024
  • are often used as synonyms for "egg-shaped". In a projective plane a set Ω of points is called an oval, if: Any line l meets Ω in at most two points, and...
    7 KB (859 words) - 23:51, 29 August 2024
  • Language Cassini oval Oval (projective plane) The Oval, Singapore, a road within Seletar Aerospace Park off Seletar Aerospace Drive Oval, London, a district...
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  • infinity Projective line Projective plane Oval (projective plane) Roman surface Projective space Complex projective line Complex projective plane Fundamental...
    13 KB (914 words) - 10:26, 25 December 2024
  • concept of plane duality readily extends to space duality and beyond that to duality in any finite-dimensional projective geometry. A projective plane C may...
    47 KB (5,681 words) - 11:07, 9 October 2024
  • a Desarguesian plane. The theorem of Desargues is true in all projective spaces of dimension not 2; in other words, the only projective spaces of dimension...
    10 KB (1,174 words) - 02:55, 8 February 2024
  • Thumbnail for Arc (projective geometry)
    1)-arc is called an oval and, if q is even, a (q + 2)-arc is called a hyperoval. Every conic in the Desarguesian projective plane PG(2,q), i.e., the set...
    5 KB (591 words) - 23:18, 12 March 2024
  • Thumbnail for Conic section
    } . A projective mapping is a finite sequence of perspective mappings. As a projective mapping in a projective plane over a field (pappian plane) is uniquely...
    69 KB (9,165 words) - 10:56, 1 December 2024
  • Thumbnail for Cubic plane curve
    homogeneous coordinates ⁠ ( x : y : z ) {\displaystyle (x:y:z)} ⁠ for the projective plane; or the inhomogeneous version for the affine space determined by setting...
    20 KB (2,878 words) - 06:53, 31 October 2024
  • geometry of even a plane curve C in the real projective plane. Assuming no singular points, the real points of C form a number of ovals, in other words submanifolds...
    1 KB (188 words) - 17:05, 14 April 2019
  • Thumbnail for Ovoid (projective geometry)
    In projective geometry an ovoid is a sphere like pointset (surface) in a projective space of dimension d ≥ 3. Simple examples in a real projective space...
    10 KB (1,520 words) - 23:15, 4 January 2021
  • Thumbnail for Segre's theorem
    Segre's theorem (category Theorems in projective geometry)
    nondegenerate projective conic sections. In pappian projective planes of even order greater than four there are ovals which are not conics. In an infinite plane there...
    10 KB (1,934 words) - 02:30, 23 August 2023
  • Thumbnail for Qvist's theorem
    Qvist's theorem (category Theorems in projective geometry)
    In projective geometry, Qvist's theorem, named after the Finnish mathematician Bertil Qvist [de], is a statement on ovals in finite projective planes. Standard...
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  • of points in a projective space that bears the same essential incidence properties as a quadric (conic section in a projective plane, sphere or cone...
    6 KB (936 words) - 05:56, 28 July 2017
  • in projective spaces; see § Normal form of projective quadrics, below. As the dimension of a Euclidean plane is two, quadrics in a Euclidean plane have...
    41 KB (7,405 words) - 01:46, 9 December 2024
  • "Topological projective planes", Trudy Moskov. Mat. Obschtsch., 3: 347–373 Hilbert 1899 Coxeter, H.S.M. (1993), The real projective plane, New York: Springer...
    30 KB (4,270 words) - 03:48, 2 September 2023
  • Thumbnail for Focus (geometry)
    parabola, the center of the directrix moves to the point at infinity (see Projective geometry). The directrix "circle" becomes a curve with zero curvature...
    10 KB (1,424 words) - 22:19, 18 October 2023
  • Thumbnail for Laguerre plane
    a Laguerre plane is one of the three types of Benz plane, which are the Möbius plane, Laguerre plane and Minkowski plane. Laguerre planes are named after...
    12 KB (2,237 words) - 23:08, 5 August 2024
  • therefore a rational plane algebraic curve of genus zero. The cruciform curve has three double points in the real projective plane, at x=0 and y=0, x=0...
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  • Thumbnail for Paraboloid
    of view of projective geometry, an elliptic paraboloid is an ellipsoid that is tangent to the plane at infinity. Plane sections The plane sections of...
    15 KB (2,336 words) - 04:07, 19 November 2024
  • Von Staudt conic (category Projective geometry)
    Staudt conics are not ovals in finite projective planes (desarguesian or not) of even order. In a pappian plane (i.e., a projective plane coordinatized by...
    6 KB (690 words) - 18:47, 11 April 2020
  • Thumbnail for Shape
    Shape (redirect from Plane figure)
    and size (as in, e.g., figure of the Earth). A plane shape or plane figure is constrained to lie on a plane, in contrast to solid 3D shapes. A two-dimensional...
    18 KB (2,502 words) - 16:43, 23 December 2024
  • Thumbnail for Algebraic geometry
    consideration of the projective completion of the two curves, which is their prolongation "at infinity" in the projective plane, allows us to quantify...
    61 KB (7,508 words) - 23:10, 26 December 2024
  • Thumbnail for Steiner conic
    Steiner conic (category Theorems in projective geometry)
    non-degenerate projective conic section in a projective plane over a field. The usual definition of a conic uses a quadratic form (see Quadric (projective geometry))...
    14 KB (2,212 words) - 04:43, 3 May 2024
  • Thumbnail for Curve
    plane curve is a curve for which X {\displaystyle X} is the Euclidean plane—these are the examples first encountered—or in some cases the projective plane...
    25 KB (3,648 words) - 15:32, 30 October 2024
  • geometry, Lam's problem is the problem of determining if a finite projective plane of order ten exists. The order ten case is the first theoretically...
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  • Thumbnail for Lemniscate
    Lemniscate (category Plane curves)
    torus by a plane parallel to the axis of the torus. As he observed, for most such sections the cross section consists of either one or two ovals; however...
    9 KB (1,096 words) - 19:34, 10 December 2024
  • Thumbnail for Galois geometry
    a Galois geometry may be defined as a projective space over a finite field. Objects of study include affine and projective spaces over finite fields and various...
    10 KB (1,454 words) - 11:02, 9 October 2024
  • Thumbnail for Bitangents of a quartic
    tangent to the curve in two places. These lines exist in the complex projective plane, but it is possible to define quartic curves for which all 28 of these...
    8 KB (1,048 words) - 12:18, 10 March 2024
  • Thumbnail for Set (card game)
    feature: number of shapes (one, two, or three), shape (diamond, squiggle, oval), shading (solid, striped, or open), and color (red, green, or purple). Each...
    13 KB (1,630 words) - 06:18, 21 December 2024