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A problem I should be able to solve (geometry)

  1. Mar 16, 2012 #1
    A problem I should be able to solve :( (geometry)

    This is a random problem I discovered on the internet:

    If the area of a rectangle is diminished by 36%, what are the sides of the original rectangle if the sides of the diminished one are 36mm and 48mm?

    My answer: Let a and b be the original sides (not diminished).

    ab*0,64=1728, so ab=2700. We know that c/d = 36/48 = a/b = 3/4 so a = 3/4 b

    Now: 3/4 b*b = 2700
    So b^2 = 3600
    And then b = +- sqrt of 3600, but since we want distance the answer is b=60.

    Because a = 3/4 b, we get a = 3/4 * 60 = 45.
     
  2. jcsd
  3. Mar 16, 2012 #2

    OldEngr63

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    Gold Member

    Re: A problem I should be able to solve :( (geometry)

    Where did the 1728 come from?

    Did you check your final answers? Doo they work?
     
  4. Mar 16, 2012 #3
    Re: A problem I should be able to solve :( (geometry)

    From multiplying 36 by 48 to get the area. And your answer looks correct silenzer.
     
  5. Mar 16, 2012 #4
    Re: A problem I should be able to solve :( (geometry)

    Okay, thanks. I saw a different answer elsewhere and therefore thought I was wrong. Thanks for the help.
     
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