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, \(h\) is the height, and \(\pi\) is approximately 3.14.
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Volume of a cone with a diameter of 20 cm and a height of 15 cm:
- Diameter = 20 cm, so radius \(r = \frac{20}{2} = 10\) cm
- Height \(h = 15\) cm \[ V = \frac{1}{3} \times 3.14 \times (10)^2 \times 15 = \frac{1}{3} \times 3.14 \times 100 \times 15 \] \[ V = \frac{1}{3} \times 4710 = 1570 \text{ cm}^3 \]
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Volume of a cone with a slant height of 9 in. and a base diameter of 5 in.:
- Diameter = 5 in., so radius \(r = \frac{5}{2} = 2.5\) in.
- Height \(h\) can be found using the Pythagorean theorem: \[ h = \sqrt{(9)^2 - (2.5)^2} = \sqrt{81 - 6.25} = \sqrt{74.75} \approx 8.65 \text{ in.} \] \[ V \approx \frac{1}{3} \times 3.14 \times (2.5)^2 \times 8.65 \approx \frac{1}{3} \times 3.14 \times 6.25 \times 8.65 \] \[ V \approx \frac{1}{3} \times 3.14 \times 54.0625 \approx 56.42 \text{ in}^3 \]
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Volume of a chocolate cone with a diameter of 2 cm and a height of 6 cm:
- Diameter = 2 cm, so radius \(r = \frac{2}{2} = 1\) cm
- Height \(h = 6\) cm \[ V = \frac{1}{3} \times 3.14 \times (1)^2 \times 6 = \frac{1}{3} \times 3.14 \times 1 \times 6 \] \[ V = \frac{1}{3} \times 18.84 = 6.28 \text{ cm}^3 \]
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Volume of a sandcastle mold with a diameter of 4 meters and a height of 6 meters:
- Diameter = 4 m, so radius \(r = \frac{4}{2} = 2\) m
- Height \(h = 6\) m \[ V = \frac{1}{3} \times 3.14 \times (2)^2 \times 6 = \frac{1}{3} \times 3.14 \times 4 \times 6 \] \[ V = \frac{1}{3} \times 75.36 = 25.12 \text{ m}^3 \]
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Volume of a flower vase with a radius of 5 inches and a height of 15 inches:
- Radius \(r = 5\) in.
- Height \(h = 15\) in. \[ V = \frac{1}{3} \times 3.14 \times (5)^2 \times 15 = \frac{1}{3} \times 3.14 \times 25 \times 15 \] \[ V = \frac{1}{3} \times 1177.5 \approx 392.5 \text{ in}^3 \]
Summary of Answers:
- 1570 cm³
- Approximately 56.42 in³
- 6.28 cm³
- 25.12 m³
- 392.5 in³