Tuesday, October 6, 2009

Problem 58 - GMAT Geometry


6 comments:

  1. AB = sqrt(3) * x

    (AB, BD) = 30 degrees
    (AD, DB) = 60 degrees

    BCD is an isoscless traingle.
    BC = CD = x/sqrt(2)

    Permiter = x( 1 + sqrt(3) + sqrt(2))

    B it is.

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  2. Hey Blaoism, good reasoning but you forgot to add one sqrt(2), so answer is C.

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  3. me too :(....forgot to add one sqrt(2)

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  4. A more crude method is by POE:
    We can calc AB= sqrt 3, hence the
    perimeter =(sqrt 3+1+some term)x
    now bc^2 + cd^2 = 4x^2 - choices A and B are gone, Choice C: (2Sqrt2)^2 = 4x^2 suffices.

    Not the best method but works!

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