Results 1 to 2 of 2

Math Help - internal angle sum

  1. #1
    Junior Member
    Joined
    Sep 2012
    From
    halo
    Posts
    48

    internal angle sum

    . Let A, B, C be three non-collinear points. Let D, E, F be points on the respective interiors of segments BC, AC and AB. Let θ, φ and ψ be the measures of the respective angles ∠BFC, ∠CDA and ∠AEB. Prove IAS(ABC) < θ +φ + ψ < 540 - IAS(ABC).(IAS means internal angle sum).

    There is also a picture accompanying it. Now im supposed to use the external angle inequality which is the measure of an exterior angle of a triangle is greater than that of either opposite interior angle. I don't know how to get started on this proof.
    Attached Thumbnails Attached Thumbnails internal angle sum-triangle.jpg  
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member
    Joined
    Jul 2012
    From
    INDIA
    Posts
    831
    Thanks
    209

    Re: internal angle sum

    internal angle sum-triangle-01.pnginternal angle sum-triangle-02.png I believe it should help you.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Find solutions equation in internal [0, 2pi]
    Posted in the Pre-Calculus Forum
    Replies: 3
    Last Post: May 9th 2012, 10:42 AM
  2. Circles and Internal Tangent Segments
    Posted in the Geometry Forum
    Replies: 4
    Last Post: June 18th 2011, 12:33 PM
  3. Finding the internal angles of a polygon
    Posted in the Geometry Forum
    Replies: 3
    Last Post: August 15th 2010, 02:22 AM
  4. internal direct product question
    Posted in the Advanced Algebra Forum
    Replies: 5
    Last Post: June 1st 2010, 08:25 AM
  5. internal rate of return
    Posted in the Business Math Forum
    Replies: 3
    Last Post: May 24th 2008, 11:55 AM

Search Tags


/mathhelpforum @mathhelpforum