Radius of a Circle Formula

Oct 13, 2025 by miodeya.com 78 views

Introduction

In this article, we will explore the concept of calculating the area of a circle given its diameter. The formula to calculate the area of a circle is A = πr^2, where A is the area and r is the radius of the circle. We will use this formula to calculate the area of a circle with a diameter of 8.8 m.

Understanding the Formula

The formula to calculate the area of a circle is A = πr^2. This formula is derived from the fact that the area of a circle is equal to the product of the square of its radius and the mathematical constant π (pi). The value of π is approximately 3.14.

Calculating the Radius

To calculate the area of the circle, we need to find the radius of the circle. The radius of a circle is half of its diameter. Therefore, we can calculate the radius by dividing the diameter by 2.

diameter = 8.8
radius = diameter / 2
print(radius)

Calculating the Area

Now that we have the radius, we can calculate the area of the circle using the formula A = πr^2.

import math
radius = 4.4
area = math.pi * (radius ** 2)
print(area)

Rounding the Answer to 1 d.p.

The calculated area is a decimal value. However, we are asked to round the answer to 1 decimal place (d.p.). We can use the round() function in Python to achieve this.

import math
radius = 4.4
area = math.pi * (radius ** 2)
rounded_area = round(area, 1)
print(rounded_area)

Conclusion

In this article, we have calculated the area of a circle with a diameter of 8.8 m using the formula A = πr^2. We have also rounded the answer to 1 decimal place. The final answer is 61.4.

Area of a Circle Formula

The formula to calculate the area of a circle is A = πr^2, where A is the area and r is the radius of the circle.

Radius of a Circle Formula

The radius of a circle is half of its diameter. Therefore, we can calculate the radius by dividing the diameter by 2.

Python Code

Here is the Python code to calculate the area of a circle:

import math
def calculate_area(diameter):
radius = diameter / 2
area = math.pi * (radius ** 2)
rounded_area = round(area, 1)
return rounded_area
diameter = 8.8
area = calculate_area(diameter)
print("The area of the circle is:", area)

Example Use Cases

Calculating the area of a circle with a diameter of 10 m.
Calculating the area of a circle with a diameter of 5 m.
Calculating the area of a circle with a diameter of 15 m.

Step-by-Step Solution

Calculate the radius of the circle by dividing the diameter by 2.
Calculate the area of the circle using the formula A = πr^2.
Round the answer to 1 decimal place using the round() function.

Common Mistakes

Forgetting to round the answer to 1 decimal place.
Using the wrong formula to calculate the area of a circle.
Not checking the units of the diameter and radius.
The diameter of a circle is 8.8 m. Work out the area of the circle to 1 d.p. ===========================================================

Q&A: Calculating the Area of a Circle

Q: What is the formula to calculate the area of a circle?

A: The formula to calculate the area of a circle is A = πr^2, where A is the area and r is the radius of the circle.

Q: How do I calculate the radius of a circle?

A: To calculate the radius of a circle, you need to divide the diameter by 2. The radius is half of the diameter.

Q: What is the value of π (pi)?

A: The value of π (pi) is approximately 3.14.

Q: How do I round the answer to 1 decimal place?

A: You can use the round() function in Python to round the answer to 1 decimal place.

Q: What is the final answer to the problem?

A: The final answer to the problem is 61.4.

Q: Can I use a calculator to calculate the area of a circle?

A: Yes, you can use a calculator to calculate the area of a circle. However, make sure to use the correct formula and units.

Q: What are some common mistakes to avoid when calculating the area of a circle?

A: Some common mistakes to avoid when calculating the area of a circle include:

Forgetting to round the answer to 1 decimal place.
Using the wrong formula to calculate the area of a circle.
Not checking the units of the diameter and radius.

Q: Can I use a programming language other than Python to calculate the area of a circle?

A: Yes, you can use any programming language to calculate the area of a circle. However, the formula and units will remain the same.

Q: How do I calculate the area of a circle with a diameter of 10 m?

A: To calculate the area of a circle with a diameter of 10 m, you need to follow the same steps as before:

Calculate the radius of the circle by dividing the diameter by 2.
Calculate the area of the circle using the formula A = πr^2.
Round the answer to 1 decimal place using the round() function.

Q: Can I use a spreadsheet to calculate the area of a circle?

A: Yes, you can use a spreadsheet to calculate the area of a circle. You can use the formula A = πr^2 and enter the values of the diameter and radius into the spreadsheet.

Q: What are some real-world applications of calculating the area of a circle?

A: Some real-world applications of calculating the area of a circle include:

Calculating the area of a circular room or building.
Calculating the area of a circular garden or park.
Calculating the area of a circular pipe or tube.

Q: Can I use a calculator to calculate the area of a circle with a diameter of 15 m?

A: Yes, you can use a calculator to calculate the area of a circle with a diameter of 15 m. However, make sure to use the correct formula and units.

Q: How do I calculate the area of a circle with a diameter of 5 m?

A: To calculate the area of a circle with a diameter of 5 m, you need to follow the same steps as before:

Calculate the radius of the circle by dividing the diameter by 2.
Calculate the area of the circle using the formula A = πr^2.
Round the answer to 1 decimal place using the round() function.