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Homework Help: Find length of two line segments in parallelogram.

  1. May 11, 2010 #1
    1. The problem statement, all variables and given/known data
    ABCD is a parallelogram with <BAD=60. Lines AM and BM bisect Angles BAD and ABC respectively. Perimeter of ABCD is 6. Find lengths of the sides of triangle ABM.

    [PLAIN]http://img709.imageshack.us/img709/2440/stumped.jpg [Broken]

    3. The attempt at a solution

    I'm stumped. I can't just solve for the lengths of the sides with a simple system, because there's only one value for which that 90 degree triangle will exist. I'm imagining some sort of system of equations to be setup here, but I can't put my finger on what. Can somebody give me a hint as to how best to begin this problem? SO far I've only designated lengths of the inner triangle relative to the length of the hypotenuse (one side of the perimeter of the parallelogram), but these are the special 30 - 60 - 90 length values. Thanks
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. May 11, 2010 #2


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    Notice that BMC is an equilateral triangle so BM = BC. That will give you an equation relating the short side of the parallelogram with the short leg of the right triangle. That should help.
  4. May 11, 2010 #3
    Awesome, actually that did help :p. Sometimes it's the simple things that are overlooked.
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