# Python program to find the area of a circle

Python program to find the area of a circle

This article will discuss how to find the area of a circle in Python with a given radius. The area of a circle represents the number of square units inside the circle. The following is a mathematical formula to calculate the area of a circle:

`Area = ?r² Or, Area = 3.14 * r * r`

Let us calculate it through several methods.

Method 1: Area of Circle using ? = 3.14

```#Take radius as input from user                                                                                                     r = int(input("Enter radius: "))
#Mathematical expression for the area of a circle area = 3.14 * r * r
#Print result print("The area of circle is %.4f" % area)```

Output

Here is the output:

Method 2: Area of Circle by importing math file

```#program to find the area of a circle using a math file
#import math file import math   #Take radius as input from user                                                                                                     r = int(input("Enter radius: "))
#Mathematical expression for the area of circle area = math.pi* r * r
#print result print("The area of circle is %.4f" %area)```

Output

Here is the output:

Method 3: Area of Circle using functions

```#program to calculate the area of circle using functions
#import math file import math
#Function to get area of circle def area_of_circle(r):     area = r**2 * math.pi     return area