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

Use the image to answer the question.

An oblique cone shows a base radius of 9 inches. The perpendicular height is 5 inches from the apex to the base outside the cone. A right angle is formed outside the cone to the right. A dashed diagonal line connects the center of the circular base to the apex.
What is the volume of the cone? Use 3.14 for pi.
A professional baker uses a chocolate mold to make decorations for cakes. One chocolate mold is in the shape of a cone and has a diameter of 2 cm and a height of 6 cm. What volume of chocolate, in cubic centimeters, is needed to make a solid chocolate cone? Use 3.14 for π
A sandcastle mold is in the shape of a cone, with a diameter of 4 meters and a height of 6 meters. What volume of sand is needed to fill the mold? Use 3.14 for π
A hanging flower vase is in the shape of a cone with a radius of 5 inches and a height of 15 inches. What volume of water can the flower vase hold? Use 3.14 for π
I have all of the correct answers (as I worked out the equations myself), but I just want to double check

1 answer

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

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

where \( r \) is the radius of the base and \( h \) is the height of the cone.

Let's calculate the volume for each cone you described:

1. Cone with a diameter of 20 cm and height of 15 cm

  • Diameter = 20 cm, so radius \( r = \frac{20}{2} = 10 \) cm
  • Height \( h = 15 \) cm

\[ V = \frac{1}{3} \cdot 3.14 \cdot (10^2) \cdot 15 \] \[ = \frac{1}{3} \cdot 3.14 \cdot 100 \cdot 15 \] \[ = \frac{1}{3} \cdot 4710 \] \[ = 1570 \text{ cm}^3 \]

2. Oblique cone with a base radius of 9 inches and height of 5 inches

  • Radius \( r = 9 \) inches
  • Height \( h = 5 \) inches

\[ V = \frac{1}{3} \cdot 3.14 \cdot (9^2) \cdot 5 \] \[ = \frac{1}{3} \cdot 3.14 \cdot 81 \cdot 5 \] \[ = \frac{1}{3} \cdot 1273.7 \] \[ = 424.57 \text{ in}^3 \]

3. Chocolate mold in the shape of a cone with a diameter of 2 cm and height of 6 cm

  • Diameter = 2 cm, so radius \( r = \frac{2}{2} = 1 \) cm
  • Height \( h = 6 \) cm

\[ V = \frac{1}{3} \cdot 3.14 \cdot (1^2) \cdot 6 \] \[ = \frac{1}{3} \cdot 3.14 \cdot 1 \cdot 6 \] \[ = \frac{1}{3} \cdot 18.84 \] \[ = 6.28 \text{ cm}^3 \]

4. Sandcastle mold with a diameter of 4 meters and height of 6 meters

  • Diameter = 4 m, so radius \( r = \frac{4}{2} = 2 \) m
  • Height \( h = 6 \) m

\[ V = \frac{1}{3} \cdot 3.14 \cdot (2^2) \cdot 6 \] \[ = \frac{1}{3} \cdot 3.14 \cdot 4 \cdot 6 \] \[ = \frac{1}{3} \cdot 75.36 \] \[ = 25.12 \text{ m}^3 \]

5. Hanging flower vase with a radius of 5 inches and height of 15 inches

  • Radius \( r = 5 \) inches
  • Height \( h = 15 \) inches

\[ V = \frac{1}{3} \cdot 3.14 \cdot (5^2) \cdot 15 \] \[ = \frac{1}{3} \cdot 3.14 \cdot 25 \cdot 15 \] \[ = \frac{1}{3} \cdot 1177.5 \] \[ = 392.5 \text{ in}^3 \]

Summary of Calculated Volumes:

  1. 1570 cm³
  2. 424.57 in³
  3. 6.28 cm³
  4. 25.12 m³
  5. 392.5 in³

Please double-check your answers against these calculations. If you have the answers already, compare them to the ones provided above for accuracy.