Results 1 to 5 of 5

Math Help - Geometry problem

  1. #1
    Newbie
    Joined
    Sep 2007
    Posts
    2

    Geometry problem

    In circle C - I need to find AC, AB, FE and angle DAE.



    I'm not sure how to solve it because I got confused by the teacher.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    is up to his old tricks again! Jhevon's Avatar
    Joined
    Feb 2007
    From
    New York, USA
    Posts
    11,663
    Thanks
    3
    Quote Originally Posted by jenna14 View Post
    In circle C - I need to find AC, AB, FE and angle DAE.



    I'm not sure how to solve it because I got confused by the teacher.
    is C the center? (so the radius would be 10)?

    if so, AC = AG + GC, where GC is the radius

    we can find AB using Pythagoras' theorem

    to find FE, you can draw a line from F to C and from E to C. note that you will form an isosceles triangle, with the angle at the center = 90 degrees. i think you can take it from there

    to find angle DAE ... i have to think about some more. there seems to be some useful theorem that i'm forgetting at the moment
    Follow Math Help Forum on Facebook and Google+

  3. #3
    MHF Contributor red_dog's Avatar
    Joined
    Jun 2007
    From
    Medgidia, Romania
    Posts
    1,245
    Thanks
    1
    \displaystyle\widehat{DAE}=\frac{1}{2}(arc(DE)-arc(GF))
    arc(GF)=180-60-90=30
    Then \displaystyle\widehat{DAE}=\frac{1}{2}(60-30)=15
    Follow Math Help Forum on Facebook and Google+

  4. #4
    is up to his old tricks again! Jhevon's Avatar
    Joined
    Feb 2007
    From
    New York, USA
    Posts
    11,663
    Thanks
    3
    Quote Originally Posted by red_dog View Post
    \displaystyle\widehat{DAE}=\frac{1}{2}(arc(DE)-arc(GF))
    arc(GF)=180-60-90=30
    Then \displaystyle\widehat{DAE}=\frac{1}{2}(60-30)=15
    that's the theorem i was forgetting. i thought it only worked for tangents though. that is, AE and AD had to be tangents, oh well
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Newbie
    Joined
    Sep 2007
    Posts
    2
    Thanks for the help!
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Geometry problem help!?!
    Posted in the Geometry Forum
    Replies: 2
    Last Post: March 6th 2010, 08:34 PM
  2. Replies: 2
    Last Post: January 10th 2009, 05:49 AM
  3. geometry problem
    Posted in the Geometry Forum
    Replies: 3
    Last Post: January 5th 2009, 02:01 PM
  4. Geometry problem
    Posted in the Geometry Forum
    Replies: 1
    Last Post: December 13th 2008, 05:40 PM
  5. help this geometry problem
    Posted in the Geometry Forum
    Replies: 2
    Last Post: March 26th 2008, 03:10 PM

Search Tags


/mathhelpforum @mathhelpforum