input: Write a function that prompts the user to enter the value of the radius and calculates the area of a circle. The function should return the calculated area. Use the value 3.14 for Pi.
  assert calculate_circle_area()==None
  assert calculate_circle_area()==None
  assert calculate_circle_area()==None
  assert calculate_circle_area()==None
  assert calculate_circle_area()==None
output: def calculate_circle_area():
      radius = float(input("Enter the value of the radius: "))
      area = 3.14 * radius ** 2
      return area