



def     __lowercase(	UpperCAmelCase__   ,   UpperCAmelCase__   ,   UpperCAmelCase__ ):


      """simple docstring"""



      if principal <= 0:
            raise Exception("Principal borrowed must be > 0" )
      if rate_per_annum < 0:
            raise Exception("Rate of interest must be >= 0" )
      if years_to_repay <= 0 or not isinstance(UpperCAmelCase__   ,   UpperCAmelCase__ ):
            raise Exception("Years to repay must be an integer > 0" )

      # Yearly rate is divided by 12 to get monthly rate
      lowerCamelCase								=		rate_per_annum / 12

      # Years to repay is multiplied by 12 to get number of payments as payment is monthly
      lowerCamelCase								=		years_to_repay * 12

      return (
          principal
          * rate_per_month
          * (1 + rate_per_month) ** number_of_payments
          / ((1 + rate_per_month) ** number_of_payments - 1)
      )


if __name__ == "__main__":
     import doctest

     doctest.testmod()




from math import pi

def     __lowercase(	UpperCAmelCase__   ,   UpperCAmelCase__ ):


      """simple docstring"""



      return 2 * pi * radius * (angle / 360)


if __name__ == "__main__":
     print(arc_length(9_0, 1_0))