Geometry.Net - the online learning center
Home  - Theorems_And_Conjectures - Napoleon's Theorem
e99.com Bookstore
  
Images 
Newsgroups
Page 1     1-20 of 86    1  | 2  | 3  | 4  | 5  | Next 20

         Napoleon's Theorem:     more detail
  1. Napoleon's Theorem

1. Napoleon's Theorem - Wikivisual
In mathematics, Napoleon's theorem is a theorem that states that if equilateral triangles are constructed on the sides of any triangle, either all outward, or all inward, the
http://en.wikivisual.com/index.php/Napoleon's_theorem
Francais English
Napoleon's theorem
From Wikipedia, the free encyclopedia
Jump to: navigation search Image:Napoleon's theorem.svg In mathematics Napoleon's theorem is a theorem that states that if equilateral triangles are constructed on the sides of any triangle , either all outward, or all inward, the centroids of those equilateral triangles themselves form an equilateral triangle. The absolute difference in area of the inner and outer Napoleon triangles equals the area of the given triangle. Although he is traditionally given the credit, there is no specific evidence that Napoleon Bonaparte discovered or proved the theorem
edit External links
This article incorporates material from Napoleon's theorem on PlanetMath , which is licensed under the GFDL de:Napoleon-Dreieck fr:Théorème de Napoléon fi:Napoleonin lause ... zh:拿破侖定理
This geometry-related article is a stub . You can help Wikipedia by expanding it Retrieved from " http://en.wikivisual.com/index.php/Napoleon%27s_theorem Categories PlanetMath sourced articles Euclidean plane geometry ... Geometry stubs Views Personal tools Navigation Search Toolbox

2. Napoleon's Theorem - Wikipedia, The Free Encyclopedia
In mathematics, Napoleon 's theorem states that if equilateral triangles are constructed on the sides of any triangle, either all outward, or all inward, the centroids of those
http://en.wikipedia.org/wiki/Napoleon's_theorem
Napoleon's theorem
From Wikipedia, the free encyclopedia Jump to: navigation search In mathematics Napoleon 's theorem states that if equilateral triangles are constructed on the sides of any triangle , either all outward, or all inward, the centroids of those equilateral triangles themselves form an equilateral triangle. The triangle thus formed is called the Napoleon triangle (inner and outer). The difference in area of these two triangles equals the area of the original triangle. The theorem is often attributed to Napoleon Bonaparte (1769-1821). However, it may just date back to W. Rutherford's 1825 publication The Ladies' Diary , four years after the French emperor's death. A quick way to see that the triangle LMN is equilateral is to observe that MN becomes CZ under a clockwise rotation of 30° around A and an homothety of ratio √ with the same center and that and LN also becomes CZ after a counterclockwise rotation of 30° around B and an homotecy of ratio √ with the same center. the respective spiral similarities A(√ ,-30°) and B(√ ,30°). That implies MN = LN and the angle between them must be 60°.

3. Napoleon's Theorem - Includipedia, The Inclusionist Encyclopaedia
In mathematics, Napoleon's theorem states that if equilateral triangles are constructed on the sides of any triangle, either all outward, or all inward, the centroids of those
http://www.includipedia.com/wiki/Napoleon's_theorem
Napoleon's theorem
From Includipedia, the inclusionist encyclopedia
Jump to: navigation search Image:Napoleon's theorem.svg In mathematics Napoleon's theorem states that if equilateral triangles are constructed on the sides of any triangle , either all outward, or all inward, the centroids of those equilateral triangles themselves form an equilateral triangle. The absolute difference in area of the inner and outer Napoleon triangles equals the area of the given triangle. Although he is traditionally given the credit, there is no specific evidence that Napoleon Bonaparte discovered or proved the theorem
External links
This article incorporates material from Napoleon's theorem on PlanetMath , which is licensed under the GFDL Image:POV-Ray-Dodecahedron.svg This geometry-related article is a stub . You can help Wikipedia by expanding it de:Napoleon-Dreieck fr:Théorème de Napoléon he:משולשי נפוליאון ... zh:拿破侖定理 Retrieved from " http://www.includipedia.com/wiki/Napoleon%27s_theorem

4. Napoleon's Theorem @ Top40-Charts.info
Napoleon's theorem information article In mathematics, Napoleon 's theorem states that if equilateral triangles are constructed on the sides of any triangle, either all outward, or all
http://www.top40-charts.info/?title=Napoleon's_theorem

5. File:Napoleon's Theorem.svg - Wikipedia, The Free Encyclopedia
napoleon's_theorem.svg ‎ (SVG file, nominally 315 333 pixels, file size 8 KB)
http://en.wikipedia.org/wiki/File:Napoleon's_theorem.svg
File:Napoleon's theorem.svg
From Wikipedia, the free encyclopedia Jump to: navigation search
(SVG file, nominally 315 × 333 pixels, file size: 8 KB) This is a file from the Wikimedia Commons . Information from its description page there is shown below. Commons is a freely licensed media file repository. You can help
edit Summary
This article incorporates material from theorem on PlanetMath , which is licensed under the GFDL
edit Licensing
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License , Version 1.2 or any later version published by the Free Software Foundation ; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled GNU Free Documentation License www.gnu.org/copyleft/fdl.html GFDL GNU Free Documentation License true true
This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license.
You are free:
  • to share – to copy, distribute and transmit the work

6. Napoleon's Theorem By The SwissPedia, The Free Encyclopedia By Just Click Search
Napoleon's theorem. The biggest multilingual freecontent encyclopedia on the Internet. Over 7 million articles in over 200 languages, and still growing.
http://www.swisscorner.com/wiki.php?title=Napoleon's_theorem

7. Napoleon's Theorem
In mathematics, Napoleon's theorem states that if equilateral triangles are constructed on the sides of any triangle, either all outward, or all inward, the
http://pediaview.com/openpedia/Napoleon's_theorem
Napoleon's theorem
In mathematics Napoleon 's theorem states that if equilateral triangles are constructed on the sides of any triangle , either all outward, or all inward, the centroids of those equilateral triangles themselves form an equilateral triangle. The triangle thus formed is called the Napoleon triangle (inner and outer). The difference in area of these two triangles equals the area of the original triangle. The theorem is often attributed to Napoleon Bonaparte (1769-1821). However, it may just date back to W. Rutherford's 1825 publication The Ladies' Diary , four years after the French emperor's death. A quick way to see that the triangle LMN is equilateral is to observe that MN becomes CZ under a clockwise rotation of 30° around A and an homothety of ratio √ with the same center and that and LN also becomes CZ after a counterclockwise rotation of 30° around B and an homotecy of ratio √ with the same center. the respective spiral similarities A(√ ,-30°) and B(√ ,30°). That implies MN = LN and the angle between them must be 60°.
See also
Notes
  • See Napoleon's Theorem via Two Rotations on the Napoleon's Theorem and Generalizations webpage (reference below)
  • External links

    8. Napoleon\'s Theorem - Wikipedia, The Free Encyclopedia
    Wikipedia does not have an article with this exact name. Please search for Napoleon\'s theorem in Wikipedia to check for alternative titles or spellings.
    http://danpritchard.com/wiki/Napoleon's_theorem
    Napoleon's theorem edit
    extracted from Wikipedia, the Free Encyclopedia (using Wikipedia Reflection Script
    From Wikipedia, the free encyclopedia Jump to: navigation search Look for on one of Wikipedia's sister projects Wiktionary (free dictionary) Wikibooks (free textbooks) Wikiquote (quotations) Wikisource (free library) Wikiversity (free learning resources) Commons (images and media) Wikinews (free news source) Wikipedia does not have an article with this exact name. Please search for in Wikipedia to check for alternative titles or spellings. Other reasons this message may be displayed:
    • If a page was recently created here, it may not yet be visible because of a delay in updating the database; wait a few minutes and try the purge function. Titles on Wikipedia are case sensitive except for the first character; please check alternative capitalizations and consider adding a redirect here to the correct title.

    9. Napoleon\'s_theorem - Encyclopedia Of Plants
    Plantspedia does not have an article with this exact name, however it may be added soon.
    http://plantspedia.org/info/Napoleon's_theorem

    10. Napoleon's Theorem
    Napoleon s theorem states that if we construct equilateral triangles on the sides of any triangle (all outward or all inward), the centers of those
    http://www.mathpages.com/home/kmath270/kmath270.htm
    Napoleon's Theorem Napoleon's theorem states that if we construct equilateral triangles on the sides of any triangle (all outward or all inward), the centers of those equilateral triangles themselves form an equilateral triangle, as illustrated below. This is said to be one of the most-often rediscovered results in mathematics. The earliest definite appearance of this theorem is an 1825 article by Dr. W. Rutherford in "The Ladies Diary". Although Rutherford was probably not the first discoverer, there seems to be no direct evidence supporting any connection with Napoleon Bonaparte, although we know that he did well in mathematics as a school boy. According to Markham 's biography, To his teachers Napoleon certainly appeared a model and promising pupil, especially in mathematics... The school inspector reported that Napoleon's aptitude for mathematics would make him suitable for the navy, but eventually it was decided that he should try for the artillery, where advancement by merit and mathematical skill was much more open... Even after becoming First Consul he was proud of him membership in the Institute de France (the leading scientific society of France ), and was close friends with several mathematicians and scientists, including Fourier, Monge, Laplace, Chaptal and Berthollet. (Oddly enough

    11. Napoleon's Theorem
    Napoleon's Theorem, introduction
    http://www.cut-the-knot.org/proofs/napoleon_intro.shtml

    12. Napoleon's Theorem -- From Wolfram MathWorld
    If equilateral triangles DeltaABE_(AB), DeltaBCE_(BC), and DeltaACE_(AC) are erected externally on the sides of any triangle DeltaABC, then their centers N_(AB), N_(BC), and N_(AC
    http://mathworld.wolfram.com/NapoleonsTheorem.html
    Algebra
    Applied Mathematics

    Calculus and Analysis

    Discrete Mathematics
    ... Interactive Demonstrations
    Napoleon's Theorem If equilateral triangles , and are erected externally on the sides of any triangle , then their centers , and , respectively, form an equilateral triangle (the outer Napoleon triangle . An additional property of the externally erected triangles also attributed to Napoleon is that their circumcircles concur in the first Fermat point (Coxeter 1969, p. 23; Eddy and Fritsch 1994). Furthermore, the lines , and connecting the vertices of with the opposite vectors of the erected triangles also concur at This theorem is generally attributed to Napoleon Bonaparte (1769-1821), although it has also been traced back to 1825 (Schmidt 1990, Wentzel 1992, Eddy and Fritsch 1994). Analogous theorems hold when equilateral triangles , and are erected internally on the sides of a triangle . Namely, the inner Napoleon triangle is equilateral , the circumcircles of the erected triangles intersect in the second Fermat point , and the lines connecting the vertices , and concur at Amazingly, the difference between the areas of the outer and inner Napoleon triangles equals the

    13. Napoleon's Theorem - Wolfram Demonstrations Project
    Construct external equilateral triangles on the sides of a triangle. The centers of the equilateral triangles also form an equilateral triangle.
    http://demonstrations.wolfram.com/NapoleonsTheorem/

    14. Napoleon's Theorem And Douglas' Theorem
    Attempt to spread a novel Cut The Knot! meme via the Web site of the Mathematical Association of America, Napoleon's Theorem, Douglas' Theorem
    http://www.cut-the-knot.org/ctk/Napolegon.shtml

    15. Napoleon’s Theorem And Beyond
    Napoleon’s Theorem and Beyond. John Baker, Natural Maths. Abstract. The use of Excel to explore old, wellknown geometrical theorems is set in the context of Napoleon’s Theorem.
    http://epublications.bond.edu.au/ejsie/vol1/iss2/4/
    Skip to main content
    • My Account Help About ... Iss. 2
      Napoleon’s Theorem and Beyond
      John Baker Natural Maths
      Abstract
      The use of Excel to explore old, well-known geometrical theorems is set in the context of Napoleon’s Theorem. A number of geometrical ideas are drawn into the investigation, and spreadsheet examples are given to show how Excel can effectively model such concepts. The article concludes with a generalisation with respect to lines drawn from the vertices of a triangle. The article is not written primarily from the geometrical point of view, but emphasis is placed on the role that spreadsheets can play in developing an environment in which ideas can be explored and discovered by students. The benefits of using Excel in the context of a geometric investigation are outlined in terms of student control and ease of learning of the environment together with the spreadsheet’s ability to cope with exceptions without halting.
      Recommended Citation
      Baker, John (2004) "Napoleon’s Theorem and Beyond," Spreadsheets in Education (eJSiE) : Vol. 1: Iss. 2, Article 4.

    16. Napoleon's Theorem
    the inner Napoleon triangles The theorem also works for the inner Napoleon triangle (right, in red). Here the equilateral triangles are drawn toward the
    http://www.jimloy.com/geometry/napoleon.htm
    Return to my Mathematics pages
    Go to my home page
    Napoleon's Theorem
    Apparently Napoleon Bonaparte came up with this theorem: On any triangle, draw equilateral triangles on each side. Then the lines connecting the centers of these equilateral triangles form another equilateral triangle (the one in red here). This equilateral triangle is called the outer Napoleon triangle. The theorem also works for the inner Napoleon triangle (right, in red). Here the equilateral triangles are drawn toward the inside of the original triangle. And the area of the outer Napoleon triangle, minus the area of the inner Napoleon triangle, is equal to the area of the original triangle. These diagrams were drawn with the program Cinderella Return to my Mathematics pages
    Go to my home page

    17. Math Forum: Napoleon's Theorem
    A Template for Napoleon's Theorem Explorations. Steve Weimar. Sketchpad Resources Main CIGS Page. The Investigation Draw a triangle. On the edges of the triangle, construct
    http://mathforum.org/ces95/napoleon.html
    A Template for Napoleon's Theorem Explorations
    Steve Weimar
    Sketchpad Resources Main CIGS Page
    The Investigation
    Draw a triangle. On the edges of the triangle, construct equilateral triangles. Find the centroids of the equilateral triangles and connect them to form a new triangle.
    • What is true about the new triangle?
    • What happens when you reflect each centroid over the closest edge of your original triangle? What is the difference in areas between the outer and inner Napoleanic triangles?
    • Now construct segments from the outside corners of the equilaterals triangles to the opposite vertices of the original triangle.
    • What is true about these segments?
    • What is true about these segments relative to the original triangle?
    Our Sketch and Comments
    The following sketch is one "non-geometer's" first exploration of Napoleon's theorem. Here's a link to this sketch by Sarah Seastone, for which you need The Geometer's Sketchpad.
    Home
    The Math Library Quick Reference Search ... Help
    http://mathforum.org/
    The Math Forum is a research and educational enterprise of the Goodwin College of Professional Studies Steve Weimar
    The Geometry Forum
    November, 1995

    18. Napoleon's Theorem -- Math Fun Facts
    Take any generic triangle, and construct equilateral triangles on each side whose side lengths are the same as the length of each side of the original triangle.
    http://www.math.hmc.edu/funfacts/ffiles/10009.2.shtml
    hosted by the Harvey Mudd College Math Department Francis Su The Math Fun Facts App is now in the App Store
    Subscribe to our RSS feed or
    Any Easy Medium Advanced
    The Math Fun Facts App!

    List All
    List Recent List Popular ... Francis Edward Su
    From the Fun Fact files, here is a Fun Fact at the Easy level:
    Napoleon's Theorem
    Figure 1 Take any generic triangle, and construct equilateral triangles on each side whose side lengths are the same as the length of each side of the original triangle. Surprise: the centers of the equilateral triangles form an equilateral triangle Presentation Suggestions:
    Show the truth of the statement using some extreme cases for the initial triangle (a particularly instructive example is a triangle with one sidelength very close to zero). The Math Behind the Fact:
    This theorem is credited to Napoleon, who was fond of mathematics, though many doubt that he knew enough math to discover it! How to Cite this Page:
    Su, Francis E., et al. "Napoleon's Theorem." Math Fun Facts Share Subjects: geometry
    Level: Easy
    Fun Fact suggested by: Michael Moody Suggestions? Use

    19. Napoleon's Theorem. Geometry From The Land Of The Incas - Antonio Gutierrez
    Napoleon s Theorem. Any triangle with the centers of equilateral triangles on the sides.
    http://agutie.homestead.com/files/Napoleon0.htm
    Napoleon's Theorem. Geometry from the Land of the Incas. No Frame

    20. Napoleon's Theorem And The Fermat Point
    Napoleon's Theorem and the Fermat Point. This page has a proof of Napoleon's theorem and also proofs of the main properties of the special ines and circles in this figure that
    http://www.math.washington.edu/~king/coursedir/m444a03/notes/12-05-Napoleon-Ferm
    Napoleon's Theorem and the Fermat Point
    This page has a proof of Napoleon's theorem and also proofs of the main properties of the special ines and circles in this figure that all pass through the Fermat point. The proofs use several important tools that should be reviewed, if needed. See the References section at the end for places to look. The Napoleon figure is a triangle ABC with an equilateral triangle built on each side: BCA', CAB', ABC'. The centers of the equilateral triangles are X, Y, Z, respectively.
    Napoleon's Theorem
    For any triangle ABC, the triangle XYZ is an equilateral triangle. Proof: The rotation Y maps A to C. The rotation X maps C to B. So if we define S = X Y , then S(A) = X (Y (A)) = X (C) = B. But by the theory of composition of rotations (see Brown 2.4), S is a rotation by angle 240 degrees and the center D of S is constructed as the vertex of a triangle YXD, where angle X = 120/2 = 60 degrees and angle Y also = 60 degrees. Thus YXD is an equilateral triangle. But also Z (A) = B, since Z

    Page 1     1-20 of 86    1  | 2  | 3  | 4  | 5  | Next 20

    free hit counter