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Math Help - Triangle with angle of 60 degrees

  1. #1
    Junior Member darence's Avatar
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    Triangle with angle of 60 degrees

    Hello all.
    I have a problem : Proof that triangle has an 600 angle if and only if sin3\alpha+sin3\beta+sin3\gamma=0
    Please help, no idea
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  2. #2
    MHF Contributor
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    Re: Triangle with angle of 60 degrees

    Hey darence.

    First off, we know that all angles equal 180 degrees or pi radians.

    Now y = pi - b - pi/3 so prove that sin(3*pi/3) + sin(3*b) + sin(3*(2pi/3 - b) = 0 and you're done.
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  3. #3
    Junior Member darence's Avatar
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    Re: Triangle with angle of 60 degrees

    Give me explanation. I dont understand
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  4. #4
    MHF Contributor
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    Re: Triangle with angle of 60 degrees

    Basically I set one angle to 60 degrees (or pi/3 radians) and the rest add up 180 degrees (or pi radians).

    Then you just show that the equation holds and then you're done.
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