Results 1 to 4 of 4

Math Help - Finding the missing side of a triangle?

  1. #1
    Newbie
    Joined
    Aug 2009
    Posts
    15

    Finding the missing side of a triangle?

    Okay, if you have a right triangle, the hypotenuse of which (side opposite the right angle) is 16 feet long, and the other angle is 68 degrees, how do you calculate the length of the opposite side? I have no idea how to go about finding this. Please help me.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member Matt Westwood's Avatar
    Joined
    Jul 2008
    From
    Reading, UK
    Posts
    824
    Thanks
    33
    Have you studied trigonometry at all?

    If so, you have the standard trigonometric ratios to be used: sine and cosine.

    If not, then you're probably out of your depth.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    A riddle wrapped in an enigma
    masters's Avatar
    Joined
    Jan 2008
    From
    Big Stone Gap, Virginia
    Posts
    2,551
    Thanks
    12
    Awards
    1
    Quote Originally Posted by ineedhelp87 View Post
    Okay, if you have a right triangle, the hypotenuse of which (side opposite the right angle) is 16 feet long, and the other angle is 68 degrees, how do you calculate the length of the opposite side? I have no idea how to go about finding this. Please help me.
    Hi ineedhelp87,

    It's just a little right triangle trigonometry.

    \sin A=\frac{opp}{hyp}

    \cos A=\frac{adj}{hyp}

    Let's say the hypotenuse is labeled 'c'

    One leg is labeled 'a' and the other leg is labeled 'b'

    You know that one of the acute angles is 68 degrees. Let's say that it is the angle made with the hypotenuse and leg 'b'. See diagram.

    \sin 68=\frac{a}{16}

    \cos 68 = \frac{b}{16}

    Solve these equations for 'a' and 'b', respectively, and you have what you need.
    Attached Thumbnails Attached Thumbnails Finding the missing side of a triangle?-tri.png  
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Newbie
    Joined
    Aug 2009
    Posts
    19
    Do you know Sin, Cos, and Tan?
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 0
    Last Post: November 13th 2011, 02:32 PM
  2. Finding length of the missing side
    Posted in the Algebra Forum
    Replies: 10
    Last Post: October 3rd 2011, 04:45 PM
  3. Replies: 3
    Last Post: March 16th 2011, 08:48 AM
  4. Finding side on triangle
    Posted in the Trigonometry Forum
    Replies: 10
    Last Post: June 22nd 2010, 06:06 AM
  5. Finding Missing Triangle Lengths...
    Posted in the Trigonometry Forum
    Replies: 36
    Last Post: April 1st 2008, 10:01 AM

Search Tags


/mathhelpforum @mathhelpforum