Results 1 to 5 of 5

Math Help - geometry

  1. #1
    Newbie
    Joined
    Jul 2006
    Posts
    10

    ~~**geometry**~~

    in a quadrilateral ABCD, angle ABC=40 degrees, angle BCD=100 degrees and angle CDA= 60 degrees. E is a point BC such that AE bisects the angle BAD. Find the size of the angle AED if angle BCA=44 degrees


    thanx
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Member Glaysher's Avatar
    Joined
    Aug 2006
    From
    Newton-le-Willows
    Posts
    224
    3 diagrams to illustate
    Attached Thumbnails Attached Thumbnails geometry-geometry.png  
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Member Glaysher's Avatar
    Joined
    Aug 2006
    From
    Newton-le-Willows
    Posts
    224
    Internal angles in a quadrilateral add up to 360

    So angle DAB = 160

    This is bisected by line to E so

    angle DAE = angle BAE = 80

    From second diagram angle DAC = 180 - 60 - 56 = 64

    angle CAE = angle DAE - angle DAC = 80 - 64 = 16

    angle AEC = 180 - 16 - 44 = 120

    Thinking of rest

    Stuck on rest. Needs either angle ADE or angle DEC or angle BED

    If length of AB = length of AD I have an answer
    Last edited by Glaysher; August 23rd 2006 at 03:24 AM.
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Member Glaysher's Avatar
    Joined
    Aug 2006
    From
    Newton-le-Willows
    Posts
    224
    New diagram
    Attached Thumbnails Attached Thumbnails geometry-geometry2.png  
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Member Glaysher's Avatar
    Joined
    Aug 2006
    From
    Newton-le-Willows
    Posts
    224
    Call the point where the lines cross in the centre F

    angle ADE = 100 - X

    angle DEC = 120 - X

    angle CFE = X + 16 = angle AFD

    angle CDE = X - 40

    angle DFC = 164 - X = angle AFE

    If we can find a numerical value for any of these angles we have solved it
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. [SOLVED] Finite Geometry: Young's Geometry
    Posted in the Advanced Math Topics Forum
    Replies: 0
    Last Post: September 15th 2010, 07:20 AM
  2. Geometry (1)
    Posted in the Geometry Forum
    Replies: 2
    Last Post: November 7th 2009, 06:44 PM
  3. geometry (2)
    Posted in the Geometry Forum
    Replies: 4
    Last Post: November 7th 2009, 06:41 PM
  4. geometry (3)
    Posted in the Geometry Forum
    Replies: 1
    Last Post: November 7th 2009, 07:22 AM
  5. Modern Geometry: Taxicab Geometry Problems
    Posted in the Differential Geometry Forum
    Replies: 0
    Last Post: March 30th 2009, 07:32 PM

Search Tags


/mathhelpforum @mathhelpforum