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Homework Help: Law Of Cosines Problem

  1. Jun 19, 2010 #1
    1. The problem statement, all variables and given/known data

    [PLAIN]http://img28.imageshack.us/img28/1046/mathproblemp.jpg [Broken]

    2. Relevant equations

    Law of Cosines

    3. The attempt at a solution

    I'm not really sure what to do for this problem, it looks easy but I can't figure it out. I tried # 11 and was able to find d.


    However, I don't know where to go from there.
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Jun 19, 2010 #2


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    1. What do you know about the angles of the opposite corners of a parallelogram?
    2. What do you know about the sum of the angles of a parallelogram?
  4. Jun 20, 2010 #3
    Ahh... thanks, I didn't know the basic properties of parallelograms. Now this problem is much easier.
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