Multiplying Both Sides by 3

Oct 13, 2025 by wbrum.org 67 views

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Introduction

In mathematics, the volume of a cone is a fundamental concept that is used to calculate the amount of space inside a cone-shaped object. The formula for the volume of a cone is given by:

V = (1/3)πr²h

where V is the volume, π is a mathematical constant approximately equal to 3.14, r is the radius of the base of the cone, and h is the height of the cone. In this article, we will use this formula to find the radius of a cone given its volume and height.

The Problem

The volume of a cone is given as $735\pi$ cubic millimeters, and the height is 5 millimeters. We need to find the radius of the cone.

The Formula

The formula for the volume of a cone is:

V = (1/3)πr²h

We are given the volume (V) as $735\pi$ cubic millimeters, the height (h) as 5 millimeters, and we need to find the radius (r).

Substituting the Values

Substituting the given values into the formula, we get:

$735\pi$ = (1/3)πr²(5)

Simplifying the Equation

Simplifying the equation, we get:

$735\pi$ = (5/3)πr²

Canceling Out π

Canceling out π from both sides of the equation, we get:

735 = (5/3)r²

Multiplying Both Sides by 3

Multiplying both sides of the equation by 3, we get:

2190 = 5r²

Dividing Both Sides by 5

Dividing both sides of the equation by 5, we get:

438 = r²

Taking the Square Root

Taking the square root of both sides of the equation, we get:

r = √438

Evaluating the Square Root

Evaluating the square root, we get:

r ≈ 20.88

Conclusion

Therefore, the radius of the cone is approximately 20.88 millimeters.

Example Use Case

This problem can be used as an example in a mathematics class to teach students how to use the formula for the volume of a cone to find the radius of a cone.

Step-by-Step Solution

Here are the steps to solve the problem:

Write down the formula for the volume of a cone: V = (1/3)πr²h
Substitute the given values into the formula: $735\pi$ = (1/3)πr²(5)
Simplify the equation: $735\pi$ = (5/3)πr²
Cancel out π from both sides of the equation: 735 = (5/3)r²
Multiply both sides of the equation by 3: 2190 = 5r²
Divide both sides of the equation by 5: 438 = r²
Take the square root of both sides of the equation: r = √438
Evaluate the square root: r ≈ 20.88

Frequently Asked Questions

Q: What is the formula for the volume of a cone?

A: The formula for the volume of a cone is V = (1/3)πr²h.

Q: How do I find the radius of a cone given its volume and height?

A: To find the radius of a cone given its volume and height, you can use the formula V = (1/3)πr²h and substitute the given values into the formula.

Q: What is the radius of the cone in the problem?

A: The radius of the cone in the problem is approximately 20.88 millimeters.

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Introduction

In our previous article, we discussed how to find the radius of a cone given its volume and height. In this article, we will answer some frequently asked questions related to the volume of a cone.

Q&A

Q: What is the formula for the volume of a cone?

A: The formula for the volume of a cone is V = (1/3)πr²h.

Q: How do I find the radius of a cone given its volume and height?

A: To find the radius of a cone given its volume and height, you can use the formula V = (1/3)πr²h and substitute the given values into the formula.

Q: What is the radius of the cone in the problem?

A: The radius of the cone in the problem is approximately 20.88 millimeters.

Q: How do I calculate the volume of a cone if I know the radius and height?

A: To calculate the volume of a cone if you know the radius and height, you can use the formula V = (1/3)πr²h.

Q: What is the relationship between the volume, radius, and height of a cone?

A: The volume of a cone is directly proportional to the square of the radius and the height. This means that if the radius or height of a cone increases, the volume of the cone will also increase.

Q: Can I use the formula for the volume of a cone to find the height of a cone?

A: Yes, you can use the formula for the volume of a cone to find the height of a cone. If you know the volume and radius of a cone, you can rearrange the formula to solve for the height.

Q: How do I find the volume of a cone if I know the slant height and radius?

A: To find the volume of a cone if you know the slant height and radius, you can use the formula V = (1/3)πr²h, where h is the height of the cone. You can find the height of the cone using the Pythagorean theorem: h² = r² + (slant height)².

Q: What is the significance of the π in the formula for the volume of a cone?

A: The π in the formula for the volume of a cone is a mathematical constant that represents the ratio of the circumference of a circle to its diameter. It is approximately equal to 3.14.

Q: Can I use the formula for the volume of a cone to find the radius of a cone if I know the volume and slant height?

A: Yes, you can use the formula for the volume of a cone to find the radius of a cone if you know the volume and slant height. However, you will need to first find the height of the cone using the Pythagorean theorem: h² = r² + (slant height)².

Example Use Cases

Example 1: Finding the Radius of a Cone

Suppose we know that the volume of a cone is 1000π cubic millimeters and the height is 10 millimeters. We can use the formula V = (1/3)πr²h to find the radius of the cone.

Example 2: Finding the Height of a Cone

Suppose we know that the volume of a cone is 500π cubic millimeters and the radius is 5 millimeters. We can use the formula V = (1/3)πr²h to find the height of the cone.

Example 3: Finding the Volume of a Cone

Suppose we know that the radius of a cone is 10 millimeters and the height is 15 millimeters. We can use the formula V = (1/3)πr²h to find the volume of the cone.

Conclusion

In this article, we have answered some frequently asked questions related to the volume of a cone. We have also provided example use cases to illustrate how to use the formula for the volume of a cone to find the radius, height, and volume of a cone.

Step-by-Step Solution

Here are the steps to solve the problem:

Write down the formula for the volume of a cone: V = (1/3)πr²h
Substitute the given values into the formula
Simplify the equation
Cancel out π from both sides of the equation
Solve for the radius, height, or volume of the cone

Frequently Asked Questions

Q: What is the formula for the volume of a cone?

A: The formula for the volume of a cone is V = (1/3)πr²h.

Q: How do I find the radius of a cone given its volume and height?

A: To find the radius of a cone given its volume and height, you can use the formula V = (1/3)πr²h and substitute the given values into the formula.

Q: What is the radius of the cone in the problem?

A: The radius of the cone in the problem is approximately 20.88 millimeters.

Q: How do I calculate the volume of a cone if I know the radius and height?

A: To calculate the volume of a cone if you know the radius and height, you can use the formula V = (1/3)πr²h.

Q: What is the relationship between the volume, radius, and height of a cone?

A: The volume of a cone is directly proportional to the square of the radius and the height. This means that if the radius or height of a cone increases, the volume of the cone will also increase.

Q: Can I use the formula for the volume of a cone to find the height of a cone?

A: Yes, you can use the formula for the volume of a cone to find the height of a cone. If you know the volume and radius of a cone, you can rearrange the formula to solve for the height.

Q: How do I find the volume of a cone if I know the slant height and radius?

Q: What is the significance of the π in the formula for the volume of a cone?

A: The π in the formula for the volume of a cone is a mathematical constant that represents the ratio of the circumference of a circle to its diameter. It is approximately equal to 3.14.