Circle Area
Completed
Define a constant PI = 3.14159. Read a radius (decimal) and print the area PI * r * r rounded to 2 decimal places.
Input
One decimal number r.
Output
The area, rounded to 2 places.
Example
Input
1
Output
3.14
Editor
Python
Hints
By convention constants are written in UPPER_CASE.
Use r ** 2 or r * r.
Solution explanation
Python has no real constants; UPPER_CASE names tell other programmers not to change them.
Show solution
PI = 3.14159
r = float(input())
print(round(PI * r * r, 2))