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Math Help - Angle A when three lenghts are known

  1. #1
    Newbie Bobby Bob's Avatar
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    Angle A when three lengths are known

    Hi,

    Can anybody tell me the formula for getting an angle A when I have the lengths of the 3 sides of a triangle. Ive forgotten how to do it.

    Thanks for the help
    Last edited by Bobby Bob; April 8th 2005 at 12:51 PM.
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  2. #2
    Site Founder MathGuru's Avatar
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    Finding Angle A

    To find an angle when you have the lengths of the three sides you can use the following formula:

    a^2 = b^2 + c^2 - 2(bc)cosA

    where a is the length of the side opposite A, and b and c are the lengths of the other sides.

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  3. #3
    Junior Member theprof's Avatar
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    See the picture
    bye
    Attached Thumbnails Attached Thumbnails Angle A when three lenghts are known-trigo.png  
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  4. #4
    vms
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    Newbie vms's Avatar
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    Hi prof

    How to post the images like this in the messages


    thanx
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  5. #5
    Site Founder MathMan's Avatar
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    Quote Originally Posted by vms
    Hi prof

    How to post the images like this in the messages


    thanx
    the prof created the image and then uploaded it. If you have an image you want to display you can simply attach it when you create the post
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