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Math Help - acute triangle formula needed

  1. #1
    tap
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    acute triangle formula needed

    Hello,
    An acute triangle, three perimeter side lengths are given and that is all that is given. No height, base or angles. Please give a formula to find the area of this type of triangle with only three perimeter numbers only, or explain how to find b from the perimeter. Area=1/2*b*h
    thanks
    Tap
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  2. #2
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    Heron's Formula -- from Wolfram MathWorldThis webpage is what you need.
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  3. #3
    tap
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    will this work?

    Hi and thank you for your help.
    That sight is over me, but i think i found it.

    s=9a+b+c)/2
    also
    area= square root of (s(s-a)(s-b)(s-c))


    So then will this give me the area from the perimeter?
    Last edited by tap; July 6th 2008 at 03:09 PM. Reason: trying to write it right. lol
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  4. #4
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    s = \frac{{a + b + c}}{2} is the semiperimeter.
    Then the Area = \sqrt {s\left( {s - a} \right)\left( {s - b} \right)\left( {s - c} \right)}
    That is the actual area of the triangle with sides of length a, b, & c.
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  5. #5
    tap
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    Thank you very much.

    see you.
    tap
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