text: 
  def problem2_7():
      """ computes area of triangle using Heron's formula. """
      a = float(input("Enter length of side one:"))
      b = float(input("Enter length of side two:"))
      c = float(input("Enter length of side three:"))
      s = .5*(a+b+c)
      are = s*(s-a)*(s-b)*(s-c)
      area = are**.5
      print("Area of a triangle with sides",a,b,c,"is",area)
      pass # replace this pass (a do-nothing) statement with your code
  