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Cross sectional area (NOT A QUESTION)

  1. Jun 5, 2010 #1
    Just for those who don't know a thing about cross sectional areas, I thought I'd explain.

    A cross sectional area describes the area of a flat (2-dimensional) representation of a 3-dimensional object. So if I cut a cylinder, instead of seeing two circles, I see four circles (unless there are other circles in my environment). The cross-sectional area is the area of either of the two circles.

    For a cylinder or right solid, the cross-sectional area is the area of the base.
    For a sphere, the cross sectional area is the area of a circle with the same radius (pi*r2).
    For an ellipsoid, the cross sectional area is the area of an ellipse with the same long (a) and short (b) axes (pi*ab).
    Last edited: Jun 5, 2010
  2. jcsd
  3. Jun 5, 2010 #2


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    I don't know what to say. Thanks for sharing?
  4. Jun 9, 2010 #3
    lol at landau's response
  5. Jun 14, 2010 #4
    Oh, for an oblate ellipsoid (such as Earth), where lines of latitude are circular, the area is simply pi*(r^2)
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