Python Program to Calculate the Area of a Circle

For a short answer, here is a program to calculate the area of a circle in Python:

from math import pi

def area(r):
   return pi * r ** 2

You can call this function by giving it the radius of the circle, for example:

print(area(10))

Output:

314.159....

How to Calculate the Area of a Circle in Maths

To calculate the area of the circle given the radius of the circle, use the following equation.

Circle area given radius

Sometimes you also have to calculate the area given the diameter or the circumference of the circle.

Without deriving these simple equations, here are all the three formulas to calculate the area given:

  • Radius
  • Diameter
  • Circumference

When you implement a Python program to do the job using one of these formulas depending on what you want to accomplish with the program.

Area of a Circle in Python with Radius

The area of a circle given the radius follows this formula:

Circle area given radius

To convert this formula to a Python program, you need to:

  1. Create a function.
  2. Perform the calculation given the above formula.
  3. Return the result.

Here is the implementation for calculating the area of a circle given the circumference:

from math import pi

def area(r):
   return pi * r ** 2

Area of a Circle in Python with Diameter

The area of a circle given the diameter follows this formula:

Circle area given diameter

To convert this formula to a Python program, you need to:

  1. Create a function.
  2. Perform the calculation given the above formula.
  3. Return the result.

Here is the implementation for calculating the area of a circle given the circumference:

from math import pi

def area(d):
    return (pi / 4) * d ** 2

Area of a Circle in Python with Circumference

The area of a circle given the circumference follows this formula:

Circle area given circumference

To convert this formula to a Python program, you need to:

  1. Create a function.
  2. Perform the calculation given the above formula.
  3. Return the result.

Here is the implementation for calculating the area of a circle given the circumference:

from math import pi


def area(c):
    return (c ** 2) / (4 * pi)

Conclusion

Today you learned the equation(s) to calculate the area of a circle.

You also learned how to create a Python program to calculate the area for you.

Thanks for reading.

I hope you enjoy it!

Further Reading

Error Handling in Python

Python Interview Questions

Share on facebook
Share on twitter
Share on linkedin

Leave a Comment

Your email address will not be published.