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Another challenging question, no sine and no cosine law

  1. May 6, 2009 #1
    This is the 3rd problem from the book, The Unsolvable and the Solvable.

    This is the last one I post from this book. It is pretty challenging.

    Once again, it is NOT a homework problem.

    Consider an isoceles triangle ABC and an equilateral triangle BCD which share the side BC as shown below. IGNORE the dotted lines in the diagram.


    .........................A


    ..................D
    ...................................E

    ..............B_______________C



    ..........................D


    D is a point on side AB and E is a point on side AC.

    angle DAE=20 degrees
    angle DEA=20 degrees
    angle EDC=10 degrees
    angle ECD=10 degrees
    angle DBC=80 degrees
    angle DCB=70 degrees
    angle BDC=30 degrees

    WITHOUT using the sine and the cosine law, determine angle EDC
     
  2. jcsd
  3. May 6, 2009 #2

    CRGreathouse

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    I'd say no solution.
     
  4. May 7, 2009 #3
    There are two points labeled D! This is not a well defined problem.
     
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