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Thread: Mathematical Restart...

  1. Jul 25th, 2002, 05:07 PM #1
    DavidHooper
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    Mathematical Restart...

    As an easy restart into the ways of the math, here is a quick question. First correct answer (there are more than one) wins.

    The question is:
    "Devise a formula for the area of a regular polygon with the following variables:
    n - number of sides
    l - length of each side"


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  2. Jul 25th, 2002, 09:58 PM #2
    Guv
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    Easier to develop an algorithm, thinking of the regular polygon as being made of N isosceles triangles.

    Angle = Pi / N, which is half the angle opposite the base of triangle.

    Height = Length / 2*Tan(Angle), which is height of a triangle

    Area = N*Length*Height / 2


    Area = N*length2 / 4*Tan( Pi / N ), if I made the substitutions correctly.
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  3. Jul 26th, 2002, 04:42 AM #3
    JohnVB6
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    Area = (L^2 * N) / (4 * Tan(pi / N)) 'radians
    Area = (L^2 * N) / (4 * Tan(180 / N)) 'degrees

    In VB the Tan function expects radians. If N = 0, 1, 2 an error should occur, however, since pi is not exact the above formula for radians will not catch the errors for 1 or 2 sides.
    Last edited by JohnVB6; Jul 26th, 2002 at 03:43 PM.
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  4. Jul 26th, 2002, 07:31 AM #4
    transcendental
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    Can u tell me when N will be 0, 1 or 2 for a polygon?
    Last edited by transcendental; Jul 26th, 2002 at 07:34 AM.
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  6. Jul 26th, 2002, 03:24 PM #5
    JohnVB6
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    If the formulas are used in VB you must consider every possibility regarding user interaction.
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  7. Jul 26th, 2002, 05:06 PM #6
    DavidHooper
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    Yeh both correct Guv and JohnVB6. Someone else post a new thread now.
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