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Math Help - need help, please!

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    Smile need help, please!

    1. In the examination figure the sides of the triangle b=501, c=392.6, d=512.8 find the area to the nearest 10 square feet
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    Quote Originally Posted by hamadouousmane View Post
    1. In the examination figure the sides of the triangle b=501, c=392.6, d=512.8 find the area to the nearest 10 square feet
    Do a search for Heron's formula.

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    Quote Originally Posted by hamadouousmane View Post
    1. In the examination figure the sides of the triangle b=501, c=392.6, d=512.8 find the area to the nearest 10 square feet
    There are two methods. I've showed both.

    ____________________

    1st method, Heron's Formula:

    s = \frac{(a+b+c)}{2} = \frac{(501+392.6+512.8}{2} = 703.2
     a = \sqrt{(703.2)(703.2 - 501)(703.2 - 392.6)(703.2 - 512.8)} = 91700 \mathrm {units} ^2

    ____________________

    2nd method, Geometry:
    EDIT: I have attached a diagram so you can see how it is geometrically.

    Find the height by using Pythagoras and then use the standard triangle area formula.
    x^2 + h^2 = 501^2 ---------(1)
    (392.6 - x)^2 + h^2 = 512.8^2 --------------(2)
    (2) - (1)
    (392.6 - x)^2 - x^2 = 512.8^2 - 501^2
    Solve for x:
    x = 181
    Substitute x value into formula (1) or (2) to get h.
    h = 467
    \mathrm {Area} = \frac{1}{2}(\mathrm {Base})(\mathrm {Height}) = \frac{1}{2} (392.6)(467) = 91700 \mathrm {units} ^2
    Attached Thumbnails Attached Thumbnails need help, please!-diagram.jpg  
    Last edited by Simplicity; April 4th 2008 at 11:16 AM. Reason: Attaching a diagram (Triangle Image) for 2nd method
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