1. Not finding help here? Sign up for a free 30min 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!

Urgent: Basic Trigonometry

  1. Jul 22, 2012 #1
    Hello Guys

    could you please help me to find the hypotenuse for the red triangle please.



    regards
     

    Attached Files:

    • lst.JPG
      lst.JPG
      File size:
      8.1 KB
      Views:
      146
  2. jcsd
  3. Jul 22, 2012 #2

    jedishrfu

    Staff: Mentor

    you have a 3-4-5 right triangle the hyp is bisected

    with a little thought you have the answer before you
     
  4. Jul 22, 2012 #3
    thanks jedishrfu for your reply but can you explain to me more, because i did't understand what did you mean pls.

    regards
     
  5. Jul 22, 2012 #4
    First use the Pythagorean theorem to solve for the hypotenuse of the left triangle, you will get the ratios of all the sides you need and solving for (??) will be a simple algebra problem.
     
  6. Jul 22, 2012 #5

    HallsofIvy

    User Avatar
    Staff Emeritus
    Science Advisor

    There is NO red triangle. What you have in red is a trapezoid. Do you mean the triangle all the way up to the vertex of the large triangle? If so, you know that its legs have length 3 and 4 and you can find the length of the hypotenuse using the Pythagorean theorem. If you actually mean the length of the red section as shown, you will need more information. jedishrfu is assuming that the red goes half way up the small triangle but I don't see any reason to assume that.

    By the way- with the lengths as given, the angle can't be exactly 40 degrees, though it is pretty close- about 38.6 degrees.
     
  7. Jul 22, 2012 #6
    Is it possible that the large triangle isn't a right triangle?

    There is nothing that I see to indicate that it has to be.
     
  8. Jul 22, 2012 #7

    jedishrfu

    Staff: Mentor

    yes, good point. why mention theta=40 and not show the right angle? This is another one of those "don't trust the diagram" problems. I retract my original suggestion, I was fooled by the apparent 3-4-5 triangle.
     
  9. Jul 22, 2012 #8
    the angle i assumed it, not real value. Got it? please help guy

    tnx
     
  10. Jul 22, 2012 #9

    jedishrfu

    Staff: Mentor

    if you're saying its a rt triangle then you have the answer from my original post
     
  11. Jul 22, 2012 #10

    LCKurtz

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Not unless you know how far up the little triangle the red goes.
     
  12. Jul 22, 2012 #11

    SammyS

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member

    Here's that image displayed directly:
    attachment.php?attachmentid=49262&d=1342981485.jpg

    There's a red trapezoid, but as HallsofIvy said, there's no red triangle !
     
  13. Jul 23, 2012 #12
    I feel like the diagram doesn't have nearly enough clarity to answer this question.

    Are the sides of the quadralateral in the bottom right of the triangle perpindicular to the sides of the triangle, or is the quad a parallelgram?
     
  14. Jul 23, 2012 #13
    yes Villyer , the quadrilateral is perpendicular to the sides of the triangle.

    Tq
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Urgent: Basic Trigonometry
  1. Trigonometry expansion (Replies: 1)

  2. Trigonometry question (Replies: 6)

  3. A Trigonometry Problem (Replies: 15)

  4. Trigonometry Problem (Replies: 3)

Loading...