Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Fun math problem from IMO 2007

  1. Aug 28, 2009 #1
    2. Consider five points A, B, C, D and E such that ABCD is a parallelogram and BCED is a cyclic quadrilateral. Let [itex]l[/itex] be a line passing through A. Suppose that [itex]l[/itex] intersects the interior of the segment DC at F and intersects line BC at G. Suppose also that EF = EG = EC. Prove that [itex]l[/itex] is the bisector of angle DAB.
     
  2. jcsd
  3. Aug 28, 2009 #2
    the ordering doesn't work out quite correct. is it BCED or BEDC ?
     
  4. Aug 28, 2009 #3
    It is BCED.
     
  5. Aug 28, 2009 #4
    then it is not a quadrilateral ... the diagram doesnt work out properly
     
  6. Aug 28, 2009 #5

    uart

    User Avatar
    Science Advisor

    "intersects line BC at G."

    Shouldn't that read : intersects line BC extended at G. ?
     
  7. Aug 28, 2009 #6
    No the original wording is correct. He said line (infinitely long), not line segment. It doesn't really make sense to speak of extending a line.
     
  8. Aug 28, 2009 #7

    uart

    User Avatar
    Science Advisor

    Ok so it doesn't intersect the line segment BC, that's all the clarification I was looking for.
     
  9. Aug 28, 2009 #8
    nirax, my problem wordings are correct. Please look again and think about it a little bit more.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Fun math problem from IMO 2007
  1. Fun math proof (Replies: 18)

  2. To make maths fun (Replies: 5)

Loading...