<filename>Computer science/Programming languages/Python/Python libraries/Math/Math functions/area_circle.py
# Write a program that reads an integer that represents the radius
# of a given circle and calculates its area. To calculate the area of
# a circle, use the following formula: S = πr^2.

# Sample Input 1:
# 5 

# Sample Output 1:
# 78.54
from math import pi
print(round(int(input()) ** 2 * pi, 2))
<filename>Computer science/Programming languages/Python/Python libraries/Math/Math functions/area_circle.py
# Write a program that reads an integer that represents the radius
# of a given circle and calculates its area. To calculate the area of
# a circle, use the following formula: S = πr^2.

# Sample Input 1:
# 5 

# Sample Output 1:
# 78.54
from math import pi
print(round(int(input()) ** 2 * pi, 2))
# Write a program that reads an integer that represents the radius # of a given circle and calculates its area. To calculate the area of # a circle, use the following formula: S = πr^2. # Sample Input 1: # 5 # Sample Output 1: # 78.54