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Math Help - Triangle question

  1. #1
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    Unhappy Triangle question

    Hi all,

    I have a triangle in 3d space which I know the coordinates for two of its vertices A(1,2,3) and B(-1,-2,-3). I also know all the angles of the triangle and all the AB, AC and BC lengths. How can I find the x, y and z coordinates for the last vertex C?

    Thanks
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  2. #2
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    Hello, mohammad.ashtari!

    I have a triangle in 3-space.
    I know the coordinates for two of its vertices A(1,2,3) and B(-1,-2,-3).
    I also know all the angles of the triangle and all the AB, AC and BC lengths.

    How can I find the x, y and z coordinates for the last vertex C?
    There is an infinite number of solutions . . .


    With the given information, you can locate a vertex C.
    Code:
                C
                *
               *  *
              *     *
             *        *
            *           *
           *              *
        --*--*--*--*--*--*--*--
          A                 B

    But the triangle can be revolved about the side AB.

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  3. #3
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    Hi Soroban,

    Thanks for your reply. Would you please show me one of the solutions?

    Mohammad
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  4. #4
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    Hello, mohammad.ashtari!

    Would you please show me one of the solutions?
    It's a very messy problem, but I can start it for you.
    But you must provide me with some constants.
    . . The lengths of AC and BC would be useful.


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  5. #5
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    Hi,

    I have the answer but I want to find to a general solution to apply for other problems that I do not have their answers. You can use any arbitrary angle and length you want.

    Thanks,

    Mohammad
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  6. #6
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    Smile first tel......

    [quote=mohammad.ashtari;332920]Hi all,

    I have a triangle in 3d space which I know the coordinates for two of its vertices A(1,2,3) and B(-1,-2,-3). I also know all the angles of the triangle and all the AB, AC and BC lengths. How can I find the x, y and z coordinates for the last vertex ?


    my friend first u should tell me what r th angles then we can do something ..........



    thnks in advance
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