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Math Help - How to find the altitude (height) of a triangle

  1. #1
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    How to find the altitude (height) of a triangle

    Please help me, I am completely baffled. I need the formula to find the altitude/height of a triangle (in order to calculate the area, b*h/2) based on the lengths of the three sides. Please, someone help me... I really need it. I searched google and couldn't find anything.
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  2. #2
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    Use the rule of sines for area:

    A = \frac{1}{2}absin(C)

    where A is area
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  3. #3
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    Quote Originally Posted by ineedhelp87 View Post
    Please help me, I am completely baffled. I need the formula to find the altitude/height of a triangle (in order to calculate the area, b*h/2) based on the lengths of the three sides. Please, someone help me... I really need it. I searched google and couldn't find anything.
    If you know the lenghts of the three sides, the area follows from Heron's formula.
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    I have to admit, I didn't really understand the rule of sines... I think I understand Heron's formula though. So does that mean that a triangle with side lengths of 12, 15, and 7 would have an area of 41.231...?

    Thank you so much for your help. Sorry to be a mouse with a cookie but if someone could tell me if the answer I got is right so I can make sure I understood everything I would really appreciate it!
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  5. #5
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    Quote Originally Posted by ineedhelp87 View Post
    I have to admit, I didn't really understand the rule of sines... I think I understand Heron's formula though. So does that mean that a triangle with side lengths of 12, 15, and 7 would have an area of 41.231...?
    Yes that is correct.
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  6. #6
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    Quote Originally Posted by Plato View Post
    Yes that is correct.
    Okay, thank you!!
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