"""
A constant is a type of variable whose value cannot be changed


A constant is a special variable.

"""
import py200703_python1.day05_py200717.myconst as myconst


# Gravity = 9.8


r = 3
# area = py200703_python1.day05_py200717.myconst.PI * r *r
area = myconst.PI * r *r
print(area)
