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Math Help - Need help with this example.

  1. #1
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    Need help with this example.

    An observer in a helicopter 250 m above ground notes that the angle of the depression of the top of the tree is 18 degrees. Tree height is 12 m. How far from directly below the helicopter is the tree??

    How do I figure this out with trig ratios.
    Explain, so I can see what is done.
    Thanks
    Joanne

    I can't figure out how the picture of this would look like. is the helicopter above the tree??? and if so, how do you figure out the height?? I am lost on this one. thanks
    Last edited by bradycat; March 25th 2010 at 03:20 PM.
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  2. #2
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    Quote Originally Posted by bradycat View Post
    An observer in a helicopter 250 m above ground notes that the angle of the depression of the top of the tree is 18 degrees. Tree height is 12 m. How far from directly below the helicopter is the tree??

    How do I figure this out with trig ratios.
    Explain, so I can see what is done.
    Thanks
    Joanne

    I can't figure out how the picture of this would look like. is the helicopter above the tree??? and if so, how do you figure out the height?? I am lost on this one. thanks
    Complete a right angled triangle using the helicopter and the top of the try. The vertical side h is (250 - 12) m. Horizontal side d is the required distance. The angle is given. Find d.
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  3. #3
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    The question says, depression of the top of the tree of 18 degrees.
    So that means the angle is facing down from the horizontal line from the top of the tree right????

    Is the depression of the top of the tree is what is confusing me.
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  4. #4
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    Quote Originally Posted by sa-ri-ga-ma View Post
    Complete a right angled triangle using the helicopter and the top of the try. The vertical side h is (250 - 12) m. Horizontal side d is the required distance. The angle is given. Find d.


    The question says, depression of the top of the tree of 18 degrees.
    So that means the angle is facing down from the horizontal line from the top of the tree right????

    Is the depression of the top of the tree is what is confusing me.
    If the plane in just above the tree, how does the angle play in this, if its asking how far is the plane from the tree. 238m??????
    So the plane is right above the tree?? That is where I am lost.
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  5. #5
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  6. #6
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    Quote Originally Posted by skeeter View Post

    So is the answer 732.4887 M???????

    Tan 18 deg = 238/a which is the hyp.
    Tks
    J

    That helped, as long as I understood it right.
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  7. #7
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    Your answer is correct.
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  8. #8
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    Hello bradycat
    Quote Originally Posted by bradycat View Post
    So is the answer 732.4887 M???????

    Tan 18 deg = 238/a which is the hyp.
    Tks
    J

    That helped, as long as I understood it right.
    Your answer is correct, but, of course, you mean a is the adjacent.

    Grandad
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