What is the volume of a cone with a diameter of 20 cm and a height of 15 cm? Use 3.14 for pi

1. 1,570 cubic centimeters
2. 6,280 cubic centimeters
3. 314 cubic centimeters
4. 2,355 cubic centimeters

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, and \( h \) is the height.

Given the diameter of the cone is 20 cm, the radius \( r \) would be:

\[ r = \frac{\text{diameter}}{2} = \frac{20 , \text{cm}}{2} = 10 , \text{cm} \]

The height \( h \) is given as 15 cm.

Now substitute the values into the volume formula:

\[ V = \frac{1}{3} \times 3.14 \times (10 , \text{cm})^2 \times 15 , \text{cm} \]

Calculating \( (10 , \text{cm})^2 \):

\[ (10 , \text{cm})^2 = 100 , \text{cm}^2 \]

Now substitute that back into the volume formula:

\[ V = \frac{1}{3} \times 3.14 \times 100 , \text{cm}^2 \times 15 , \text{cm} \]

Next, calculate \( 3.14 \times 100 \):

\[ 3.14 \times 100 = 314 \]

Now substitute that value:

\[ V = \frac{1}{3} \times 314 , \text{cm}^2 \times 15 , \text{cm} \]

Now calculate \( 314 \times 15 \):

\[ 314 \times 15 = 4710 , \text{cm}^3 \]

Finally, divide by 3:

\[ V = \frac{4710 , \text{cm}^3}{3} = 1570 , \text{cm}^3 \]

Thus, the volume of the cone is:

\[ \boxed{1,570} \text{ cubic centimeters} \]

The correct answer is 1. 1,570 cubic centimeters.