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Finging an angle

  1. Mar 7, 2010 #1
    1. The problem statement, all variables and given/known data

    http://img341.imageshack.us/img341/1513/omfgc.png [Broken]

    ABCD is a square, CP is a radius for a circle, CP and DB intersect in Q, ABP=30 degrees, find DQC.

    2. Relevant equations


    3. The attempt at a solution

    DBP is 15 degrees, thats what I've found out. Nothing else.

    Its not a homework question, I randomly found it on the internet and now I cant get peace until I get how its supposed to be solved.
    Please give me a hint or something.

    Thanks in advance,
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Mar 7, 2010 #2
    Never mind guys. I figured it out. This thread can be closed/deleted.
    It was actually so easy that Im imbarrased I even posted this. :blushing:
    But I can be retarded sometimes.

    Anyway, whoever is interested in the solution:
    CP=BC, because both are the radius of the circle. But because DB is the diagonal of the square, DBC=45 degrees and so PBD=90-45-30=15 degrees.
    Now we get PBC=45+15=60 degrees. But because PC=CB, we get that CPB=60 degrees aswell. And now we get that PCB=180-60-60=60 degrees also.
    And now we can calculate CQB=180-60-45=75 degrees.
    Then we can easily get DQC=180-75=105 degrees.
    Last edited: Mar 7, 2010
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