input: Write a python function to calculate the area of a circle given its radius.
  assert calculate_area_of_circle(5.5) == 95.03317777109125
  assert calculate_area_of_circle(10) == 314.1592653589793
  assert calculate_area_of_circle(0) == 0
output: def calculate_area_of_circle(radius):
      import math
      return math.pi * radius ** 2