When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. D. R. Kaprekar - Wikipedia

    en.wikipedia.org/wiki/D._R._Kaprekar

    Another class of numbers Kaprekar described are Kaprekar numbers. [10] A Kaprekar number is a positive integer with the property that if it is squared, then its representation can be partitioned into two positive integer parts whose sum is equal to the original number (e.g. 45, since 45 2 =2025, and 20+25=45, also 9, 55, 99 etc.)

  3. Nine-point circle - Wikipedia

    en.wikipedia.org/wiki/Nine-point_circle

    The nine-point circles are all congruent with a radius of half that of the cyclic quadrilateral's circumcircle. The nine-point circles form a set of four Johnson circles. Consequently, the four nine-point centers are cyclic and lie on a circle congruent to the four nine-point circles that is centered at the anticenter of the cyclic quadrilateral.

  4. Circle - Wikipedia

    en.wikipedia.org/wiki/Circle

    Book 3 of Euclid's Elements deals with the properties of circles. Euclid's definition of a circle is: A circle is a plane figure bounded by one curved line, and such that all straight lines drawn from a certain point within it to the bounding line, are equal. The bounding line is called its circumference and the point, its centre.

  5. Incircle and excircles - Wikipedia

    en.wikipedia.org/wiki/Incircle_and_excircles

    The nine-point circle is tangent to the incircle and excircles. In geometry, the nine-point circle is a circle that can be constructed for any given triangle. It is so named because it passes through nine significant concyclic points defined from the triangle. These nine points are: [28] [29] The midpoint of each side of the triangle; The foot ...

  6. Tangent lines to circles - Wikipedia

    en.wikipedia.org/wiki/Tangent_lines_to_circles

    An inversion in their tangent point with respect to a circle of appropriate radius transforms the two touching given circles into two parallel lines, and the third given circle into another circle. Thus, the solutions may be found by sliding a circle of constant radius between two parallel lines until it contacts the transformed third circle.

  7. Close-packing of equal spheres - Wikipedia

    en.wikipedia.org/wiki/Close-packing_of_equal_spheres

    Édouard Lucas formulated the problem as the Diophantine equation = = or (+) (+) = and conjectured that the only solutions are =, =, and =, =. Here N {\displaystyle N} is the number of layers in the pyramidal stacking arrangement and M {\displaystyle M} is the number of cannonballs along an edge in the flat square arrangement.

  8. Gauss circle problem - Wikipedia

    en.wikipedia.org/wiki/Gauss_circle_problem

    This problem is known as the primitive circle problem, as it involves searching for primitive solutions to the original circle problem. [9] It can be intuitively understood as the question of how many trees within a distance of r are visible in the Euclid's orchard , standing in the origin.

  9. Six circles theorem - Wikipedia

    en.wikipedia.org/wiki/Six_circles_theorem

    The chain closes, in the sense that the sixth circle is always tangent to the first circle. [1] [2] It is assumed in this construction that all circles lie within the triangle, and all points of tangency lie on the sides of the triangle. If the problem is generalized to allow circles that may not be within the triangle, and points of tangency ...