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Math Help - Diameter question.

  1. #1
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    Diameter question.

    A circular pizza with a 16-inch diameter is cut into 12 equal slices. What is the are, in square inches, of each slice?
    I got the answer 4/3(3.14) but the answer is 16/3(3.14).
    So it looks like they just simplified the bottom but I didn't know how they did that.
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  2. #2
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    The area of the whole pizza is given by \pi r^2 = \pi (\frac{d}{2})^2

    This gives Area of each slice = \pi (\frac{d}{2})^2 \times \frac{1}{12} = \frac{\pi d^2}{48}

    Now, replace the value of the diameter:

    Area of slice =  \frac{\pi (16)^2}{48} = \frac{16\pi}{3} in^2
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  3. #3
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    Quote Originally Posted by dnntau View Post
    A circular pizza with a 16-inch diameter is cut into 12 equal slices. What is the are, in square inches, of each slice?
    I got the answer 4/3(3.14) but the answer is 16/3(3.14).
    If you got 4/3(pi), then you used circumference instead of area.
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  4. #4
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    Hello, dnntau!

    A circular pizza with a 16-inch diameter is cut into 12 equal slices.
    What is the area of each slice?

    I got the answer: \frac{4}{3}\pi . .
    You used the wrong formula?
    . . but the answer is: \frac{16\pi}{3}

    The radius is: . r =  8\text{ inches.}

    The area is: . A \:=\:\pi r^2 \:=\:\pi(8^2) \:=\:64\pi\text{ in}^2

    Now divide by 12 . . .

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  5. #5
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    Thanks so much.
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