Results 1 to 4 of 4

Math Help - Finding the heght with bearings

  1. #1
    Newbie
    Joined
    Jun 2011
    Posts
    2

    Unhappy Finding the heght with bearings

    Bob and Shelila are standing on a road 150m apart. A tower is due north of Bob and on a bearing of 070 degrees T from Shelila. The top of the tower appears at an angle of elevation of 27 degrees to Shelila and 18 degrees to Bob.

    Find the height of the tower above the road. what assumptions need to be made?

    My attempt-
    assumptions- the location of jack from rosa and the tower.

    3 simultaneous equations:
    rosa: tan18deg= h/x (i)
    jack: tan27deg= h/y (ii)
    3rd: 150^2=x^2+y^2 - 2xy cos 70deg (iii)

    steps:
    1. make h the subject in (i)
    2. sub h=__ into (ii)
    3. make x or y the subject
    4. sub x/y=___ into (iii)
    5. solve for x/y




    this isnt working for me. please help?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Joined
    Aug 2007
    From
    USA
    Posts
    3,110
    Thanks
    2
    Please define "h".
    Please define "x".
    Please define "y".

    It might be right. Too bad we don't know what anything means.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Jun 2011
    Posts
    2
    Quote Originally Posted by TKHunny View Post
    Please define "h".
    Please define "x".
    Please define "y".

    It might be right. Too bad we don't know what anything means.

    h is height of the tower
    x is the distance from jack to the tower
    y is the distance from rosa to the tower
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor
    Joined
    Aug 2007
    From
    USA
    Posts
    3,110
    Thanks
    2
    I'd prever one more word to make these definitions clear.

    x = horizontal distance from Jack to Tower, for example. This would be different from "distance from Jack to the top of the tower.

    Rational thinking: Without solving the problem, who is closer to the tower? If you know this, you can rule out many errors.
    Last edited by TKHunny; June 5th 2011 at 04:06 PM.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. bearings
    Posted in the Trigonometry Forum
    Replies: 3
    Last Post: June 3rd 2008, 10:39 AM
  2. bearings
    Posted in the Trigonometry Forum
    Replies: 1
    Last Post: May 13th 2008, 08:30 PM
  3. finding angles using bearings
    Posted in the Trigonometry Forum
    Replies: 1
    Last Post: February 27th 2008, 09:57 PM
  4. bearings
    Posted in the Trigonometry Forum
    Replies: 2
    Last Post: October 17th 2007, 08:04 PM
  5. bearings.. help
    Posted in the Trigonometry Forum
    Replies: 6
    Last Post: October 16th 2007, 02:41 PM

Search Tags


/mathhelpforum @mathhelpforum