input: Write a function to calculate the area of a circle given its radius.
  assert Circle(5).get_area() == 78.5
  assert Circle(10).get_area() == 314.0
  assert Circle(0).get_area() == 0.0
output: import math
  
  class Circle:
      def __init__(self, radius):
          self.radius = radius
  
      def get_area(self):
          return round(math.pi * (self.radius ** 2), 1)