enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Euler's quadrilateral theorem - Wikipedia

    en.wikipedia.org/wiki/Euler's_quadrilateral_theorem

    Euler's quadrilateral theorem or Euler's law on quadrilaterals, named after Leonhard Euler (1707–1783), describes a relation between the sides of a convex quadrilateral and its diagonals. It is a generalisation of the parallelogram law which in turn can be seen as generalisation of the Pythagorean theorem .

  3. Category:Theorems about quadrilaterals - Wikipedia

    en.wikipedia.org/wiki/Category:Theorems_about...

    Theorems about quadrilaterals and circles (6 P) Pages in category "Theorems about quadrilaterals" The following 11 pages are in this category, out of 11 total.

  4. Hesse's theorem - Wikipedia

    en.wikipedia.org/wiki/Hesse's_theorem

    In geometry, Hesse's theorem, named for Otto Hesse, states that if two pairs of opposite vertices of a quadrilateral are conjugate with respect to some conic, then so is the third pair. A quadrilateral with this property is called a Hesse quadrilateral .

  5. List of theorems - Wikipedia

    en.wikipedia.org/wiki/List_of_theorems

    Van Aubel's theorem (quadrilaterals) Van der Waerden's theorem (combinatorics) Van Schooten's theorem (Euclidean geometry) Van Vleck's theorem (mathematical analysis) Vantieghems theorem (number theory) Varignon's theorem (Euclidean geometry) Vieta's formulas ; Vietoris–Begle mapping theorem (algebraic topology) Vinogradov's theorem (number ...

  6. Euclidean geometry - Wikipedia

    en.wikipedia.org/wiki/Euclidean_geometry

    Books V and VII–X deal with number theory, with numbers treated geometrically as lengths of line segments or areas of surface regions. Notions such as prime numbers and rational and irrational numbers are introduced. It is proved that there are infinitely many prime numbers. Books XI–XIII concern solid geometry. A typical result is the 1:3 ...

  7. Quadrilateral - Wikipedia

    en.wikipedia.org/wiki/Quadrilateral

    A quadric quadrilateral is a convex quadrilateral whose four vertices all lie on the perimeter of a square. [7] A diametric quadrilateral is a cyclic quadrilateral having one of its sides as a diameter of the circumcircle. [8] A Hjelmslev quadrilateral is a quadrilateral with two right angles at opposite vertices. [9]

  8. Ptolemy's theorem - Wikipedia

    en.wikipedia.org/wiki/Ptolemy's_theorem

    Moreover, the converse of Ptolemy's theorem is also true: In a quadrilateral, if the sum of the products of the lengths of its two pairs of opposite sides is equal to the product of the lengths of its diagonals, then the quadrilateral can be inscribed in a circle i.e. it is a cyclic quadrilateral.

  9. Outline of geometry - Wikipedia

    en.wikipedia.org/wiki/Outline_of_geometry

    Geometry is a branch of mathematics concerned with questions of shape, size, relative position of figures, and the properties of space. Geometry is one of the oldest mathematical sciences. Geometry is one of the oldest mathematical sciences.