A party hat is shaped like a cone. The dimensions of the party hat are shown in the diagram. (height is 8 inches, width is 6 inches)

Which measurement is closest to the volume of the party hat in cubic inches?

75.4in^3
301.6in^3
402.1in^3
100.5in^3

1 answer

To find the volume of a cone, you can use the formula:

\[ V = \frac{1}{3} \pi r^2 h \]

where:

  • \( V \) is the volume,
  • \( r \) is the radius of the base of the cone,
  • \( h \) is the height of the cone.

From the problem, the height \( h \) of the party hat (cone) is given as 8 inches. The width is 6 inches, which refers to the diameter of the base of the cone. Therefore, the radius \( r \) can be calculated as follows:

\[ r = \frac{diameter}{2} = \frac{6}{2} = 3 \text{ inches} \]

Now substituting the values \( r = 3 \) inches and \( h = 8 \) inches into the volume formula:

\[ V = \frac{1}{3} \pi (3)^2 (8) \]

Calculating this step-by-step:

  1. Calculate \( r^2 \):

\[ r^2 = 3^2 = 9 \]

  1. Substitute \( r^2 \) in the volume formula:

\[ V = \frac{1}{3} \pi (9)(8) \]

  1. Calculate \( 9 \times 8 \):

\[ 9 \times 8 = 72 \]

  1. Now substitute this into the volume formula:

\[ V = \frac{1}{3} \pi (72) \]

  1. Multiply \( 72 \) by \( \frac{1}{3} \):

\[ \frac{72}{3} = 24 \]

  1. Finally, multiply by \( \pi \):

\[ V = 24 \pi \]

Using \( \pi \approx 3.14\):

\[ V \approx 24 \times 3.14 \approx 75.36 \text{ in}^3 \]

Thus, rounding to one decimal place, the volume of the cone is approximately \( 75.4 \text{ in}^3 \).

The measurement closest to the volume of the party hat is:

\[ \boxed{75.4 , \text{in}^3} \]