When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Area of a circle - Wikipedia

    en.wikipedia.org/wiki/Area_of_a_circle

    The circumference is 2 π r, and the area of a triangle is half the base times the height, yielding the area π r 2 for the disk. Prior to Archimedes, Hippocrates of Chios was the first to show that the area of a disk is proportional to the square of its diameter, as part of his quadrature of the lune of Hippocrates , [ 2 ] but did not identify ...

  3. List of formulae involving π - Wikipedia

    en.wikipedia.org/wiki/List_of_formulae_involving_π

    where C is the circumference of a circle, d is the diameter, and r is the radius.More generally, = where L and w are, respectively, the perimeter and the width of any curve of constant width.

  4. Euler's identity - Wikipedia

    en.wikipedia.org/wiki/Euler's_identity

    is pi, the ratio of the circumference of a circle to its diameter. Euler's identity is named after the Swiss mathematician Leonhard Euler . It is a special case of Euler's formula e i x = cos ⁡ x + i sin ⁡ x {\displaystyle e^{ix}=\cos x+i\sin x} when evaluated for x = π {\displaystyle x=\pi } .

  5. Pi - Wikipedia

    en.wikipedia.org/wiki/Pi

    The number π (/ p aɪ / ⓘ; spelled out as "pi") is a mathematical constant, approximately equal to 3.14159, that is the ratio of a circle's circumference to its diameter.It appears in many formulae across mathematics and physics, and some of these formulae are commonly used for defining π, to avoid relying on the definition of the length of a curve.

  6. Surface area - Wikipedia

    en.wikipedia.org/wiki/Surface_area

    A sphere of radius r has surface area 4πr 2.. The surface area (symbol A) of a solid object is a measure of the total area that the surface of the object occupies. [1] The mathematical definition of surface area in the presence of curved surfaces is considerably more involved than the definition of arc length of one-dimensional curves, or of the surface area for polyhedra (i.e., objects with ...

  7. Circumference - Wikipedia

    en.wikipedia.org/wiki/Circumference

    Pi is defined as the ratio of a circle's circumference to its diameter: [4] =. Or, equivalently, as the ratio of the circumference to twice the radius . The above formula can be rearranged to solve for the circumference: C = π ⋅ d = 2 π ⋅ r . {\displaystyle {C}=\pi \cdot {d}=2\pi \cdot {r}.\!}

  8. Equivalent radius - Wikipedia

    en.wikipedia.org/wiki/Equivalent_radius

    US hat size is the circumference of the head, measured in inches, divided by pi, rounded to the nearest 1/8 inch. This corresponds to the 1D mean diameter. [1] Diameter at breast height is the circumference of tree trunk, measured at height of 4.5 feet, divided by pi. This corresponds to the 1D mean diameter.

  9. Gauss circle problem - Wikipedia

    en.wikipedia.org/wiki/Gauss_circle_problem

    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. If the number of such solutions is denoted V ( r ) {\displaystyle V(r)} then the values of V ( r ) {\displaystyle V(r)} for r {\displaystyle r} taking small integer values are