Math Help - Diameter question.

1. 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.

2. 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

3. Originally Posted by dnntau
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.

4. 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 . . .

5. Thanks so much.