Results 1 to 11 of 11

Math Help - Circle theorems question

  1. #1
    Junior Member
    Joined
    Jul 2012
    From
    London
    Posts
    57

    Circle theorems question

    Circle theorems question-circle.png
    Can anyone please explain to me how to get the missing answers? Thanks.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Junior Member
    Joined
    Jul 2012
    From
    London
    Posts
    57

    Re: Circle theorems question

    (just click on the pic to zoom in)
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Junior Member
    Joined
    Jul 2012
    From
    London
    Posts
    57

    Re: Circle theorems question

    I found out ABC, but I can't figure out OAD.
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Super Member
    Joined
    Nov 2007
    From
    Trumbull Ct
    Posts
    886
    Thanks
    25

    Re: Circle theorems question

    value of angles
    RCB =56
    ABC=70.5
    OAD=OAC + DCT
    CAD =DCT
    Triangle OAC is isosceles.Finish it after finding angleAOC
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Junior Member
    Joined
    Jul 2012
    From
    London
    Posts
    57

    Re: Circle theorems question

    How is ABC 70.5?
    Follow Math Help Forum on Facebook and Google+

  6. #6
    Super Member
    Joined
    Nov 2007
    From
    Trumbull Ct
    Posts
    886
    Thanks
    25

    Re: Circle theorems question

    Quote Originally Posted by Ashir View Post
    How is ABC 70.5?
    Its 1/2 of 141
    Follow Math Help Forum on Facebook and Google+

  7. #7
    Junior Member
    Joined
    Jul 2012
    From
    London
    Posts
    57

    Re: Circle theorems question

    And? Opposite angles add up to 180 is the theory. Therefor ABC is 39. Why would it be one half of 141?
    And I checked, my answers were right.
    Follow Math Help Forum on Facebook and Google+

  8. #8
    Super Member
    Joined
    Nov 2007
    From
    Trumbull Ct
    Posts
    886
    Thanks
    25

    Re: Circle theorems question

    if angle ADC =141 arc ADC =78,angle AOC =78 not obtuse as you show. I assumed that arc ADC =141
    Follow Math Help Forum on Facebook and Google+

  9. #9
    Junior Member
    Joined
    Jul 2012
    From
    London
    Posts
    57

    Re: Circle theorems question

    What arc?
    Follow Math Help Forum on Facebook and Google+

  10. #10
    Junior Member
    Joined
    Jul 2012
    From
    London
    Posts
    57

    Re: Circle theorems question

    Still in need of an answer.
    Follow Math Help Forum on Facebook and Google+

  11. #11
    Super Member
    Joined
    Nov 2007
    From
    Trumbull Ct
    Posts
    886
    Thanks
    25

    Re: Circle theorems question

    angleOAD = 74 deg Ichanged your drawimg moving A closer to C making angle AOC acute
    Last edited by bjhopper; September 27th 2012 at 06:10 PM. Reason: add word
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Circle theorems
    Posted in the Geometry Forum
    Replies: 5
    Last Post: May 10th 2011, 02:24 PM
  2. Circle Theorems
    Posted in the Geometry Forum
    Replies: 1
    Last Post: March 15th 2009, 05:46 AM
  3. circle theorems
    Posted in the Geometry Forum
    Replies: 1
    Last Post: March 4th 2009, 04:00 AM
  4. Circle Theorems
    Posted in the Geometry Forum
    Replies: 2
    Last Post: November 10th 2008, 04:56 PM
  5. Circle theorems
    Posted in the Geometry Forum
    Replies: 10
    Last Post: December 21st 2007, 05:04 PM

Search Tags


/mathhelpforum @mathhelpforum