# L-26 MCS 260 Fri 26 Oct 2007 : classcircle

from classpoint import *
class Circle(Point):
   "defines a circle derived from point"

   def __init__(self,a=0,b=0,r=0):
      "the center is (a,b), radius = r"
      Point.__init__(self,a,b)
      self.r = r 

   def area(self):
      "returns the area of the circle"
      from math import pi
      return pi*self.r**2
     
   def __str__(self):
      "returns string representation of a circle"
      s = 'center : ' + Point.__str__(self) + '\n'
      s += 'radius : ' + '%.4e' % self.r
      return s