1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Geometric proof.

  1. Aug 24, 2010 #1
    Hello all, the picture i have attached is the question.
    http://img842.imageshack.us/img842/8921/geometricproof.png [Broken]

    I've concluded that there are two i isosceles triangles in this one triangle.

    [tex]\angle[/tex]PSQ + [tex]\angle[/tex]QSR = 90degrees
    Finding the angle in one of the isosceles triangles.

    [tex]\Delta[/tex]RQS with RQ = SQ
    RQ = SQ (given)
    If we put a line through the isosceles triangle and call this Z.
    RZ = SZ
    RZ = SZ (common to both)
    therefore: [tex]\Delta[/tex]RZQ =~ [tex]\Delta[/tex]SZQ
    therefore: [tex]\Delta[/tex]QRZ = [tex]\Delta[/tex]QSZ
    which results in: [tex]\angle[/tex]QRS = [tex]\angle[/tex]QSR
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Aug 24, 2010 #2
    I dont understand your explanation on 'Z'!
    But your starting point is correct..You have two isosceles triangles (PSQ and QSR) in the triangle PSR.
    I will now give you a easy hint:
    First consider the isosceles triangle PSQ and find which two angles are equal?
    Then take the second isosceles triangle QSR and find which two angles are equal?
    Now you know the three angles of the triangle PSR = 180 degree.
    Got it!
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Geometric proof.
  1. Geometric proof (Replies: 4)

  2. Geometrical Proofs (Replies: 2)

  3. Geometrical Proof (Replies: 6)