Results 1 to 3 of 3
Like Tree2Thanks
  • 2 Post By Soroban

Math Help - circle, angle

  1. #1
    Newbie
    Joined
    Jun 2006
    Posts
    5

    circle, angle

    Hi,

    I have this problem:
    circle, angle-circle.jpg

    AC = Diameter
    DBC = 30 degree
    BDC = 35 degree
    AED = ? degree

    How can I find AED ?

    I have try to find the other angles but still can't find AED
    circle, angle-circle2.jpg

    Thank you so much for your help.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member

    Joined
    May 2006
    From
    Lexington, MA (USA)
    Posts
    11,660
    Thanks
    600

    Re: circle, angle

    Hello, dodoldotkom!

    I have this problem:
    Click image for larger version. 

Name:	circle.jpg 
Views:	4 
Size:	84.9 KB 
ID:	23447

    AC = Diameter
    DBC = 30 degree
    BDC = 35 degree
    AED = ? degree

    AC\text{ is a diameter.}
    \text{Hence: }\:\text{arc}(ABC) \,=\,\text{arc}(ADC) \,=\,180^o

    \angle DBC = 30^o \quad\Rightarrow\quad \text{arc}(DC) = 60^o

    . . \text{arc}(AD) = 120^o \quad\Rightarrow\quad \angle ACD = 60^o


    \text{In }\Delta ECD: \:\angle ECD = 60^o,\;\angle EDC = 35^o \quad\Rightarrow\quad \angle DEC = 85^o

    \text{Therefore: }\:\angle AED = 95^o

    Thanks from dodoldotkom and mash
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Jun 2006
    Posts
    5

    Re: circle, angle

    Thank you so much you are truly amazing!
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Angle in a circle.
    Posted in the Geometry Forum
    Replies: 3
    Last Post: April 22nd 2011, 05:29 PM
  2. Angle in a circle
    Posted in the Geometry Forum
    Replies: 6
    Last Post: September 9th 2010, 07:30 AM
  3. triangle in a circle rt angle
    Posted in the Geometry Forum
    Replies: 3
    Last Post: March 7th 2010, 01:56 PM
  4. Angle between two points on a circle
    Posted in the Trigonometry Forum
    Replies: 6
    Last Post: December 1st 2009, 05:11 AM
  5. help on angle in circle problem
    Posted in the Geometry Forum
    Replies: 3
    Last Post: December 9th 2008, 04:58 AM

Search Tags


/mathhelpforum @mathhelpforum