Results 1 to 6 of 6

Math Help - trig and mitre angles

  1. #1
    Tin
    Tin is offline
    Newbie
    Joined
    Oct 2012
    From
    canada
    Posts
    4

    trig and mitre angles

    Hi all,
    I just have some basic trig behind me, and i would like some understanding on how to do some calculations.
    I will insert an image as my basic model.

    trig and mitre angles-trig.jpg

    Being that the included angle is 155 degrees and the 7 inches and 4 inches are constants.
    I would like to know how to claculate for:
    angle A
    angle B
    and "L"
    in 3 different calculations.
    I would really appreciate some help on this and keep in mind, that I only have basic trig
    Thanks
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Senior Member MaxJasper's Avatar
    Joined
    Aug 2012
    From
    Canada
    Posts
    482
    Thanks
    54

    Lightbulb Re: trig and mitre angles

    sin (A) =7/L
    cos (B-90)=4/L
    A+B+155=360
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Tin
    Tin is offline
    Newbie
    Joined
    Oct 2012
    From
    canada
    Posts
    4

    Re: trig and mitre angles

    MaxJasper,
    Thank you, you won't believe how helpful that was.
    I have spent many hours (probably around 14) on a different forum trying to get that answer.
    Your answer makes sense to me, others were trying to make a molehill into a mountain and they lost me by making the problem bigger than it was.

    now, my solving for 2 unknowns with 3 equations is weak ( many many years since I've done it)
    would you mind walking me throught the steps to solve for "L"?
    thank you
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Senior Member MaxJasper's Avatar
    Joined
    Aug 2012
    From
    Canada
    Posts
    482
    Thanks
    54

    Re: trig and mitre angles

    Solve to obtain L = 8.9312"
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Tin
    Tin is offline
    Newbie
    Joined
    Oct 2012
    From
    canada
    Posts
    4

    Re: trig and mitre angles

    How did you get the answer?
    I don't want the answer, I want to learn how.
    Thanks.
    Follow Math Help Forum on Facebook and Google+

  6. #6
    Tin
    Tin is offline
    Newbie
    Joined
    Oct 2012
    From
    canada
    Posts
    4

    Re: trig and mitre angles

    can some one give me the equation to solve for L and I will try and figure it out
    thanks
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. all possible angles of a trig ratio
    Posted in the Trigonometry Forum
    Replies: 5
    Last Post: July 1st 2009, 10:03 AM
  2. Trig Angles
    Posted in the Trigonometry Forum
    Replies: 1
    Last Post: April 9th 2009, 12:59 PM
  3. Trig Angles tan2x
    Posted in the Trigonometry Forum
    Replies: 1
    Last Post: April 9th 2009, 12:03 PM
  4. Trig angles
    Posted in the Trigonometry Forum
    Replies: 1
    Last Post: January 29th 2009, 08:24 AM
  5. Trig - Finding Angles
    Posted in the Trigonometry Forum
    Replies: 1
    Last Post: June 25th 2008, 04:14 PM

Search Tags


/mathhelpforum @mathhelpforum