text: #!/usr/bin/env python
  # -*- coding: utf-8 -*-
  
  # Triangle Project Code.
  
  # Triangle analyzes the lengths of the sides of a triangle
  # (represented by a, b and c) and returns the type of triangle.
  #
  # It returns:
  #   'equilateral'  if all sides are equal
  #   'isosceles'    if exactly 2 sides are equal
  #   'scalene'      if no sides are equal
  #
  # The tests for this method can be found in
  #   about_triangle_project.py
  # and
  #   about_triangle_project_2.py
  #
  def triangle(a, b, c):
  	if a <= 0 or b <= 0 or c <= 0:
  		raise TriangleError('All sides should be greater than 0')
  
  	if (a + b) < c or (a + c) < b or (b + c) < a:
  		raise TriangleError('The sum of any two sides should be greater than the third one')
  
  	if a == b and a == c and c == a:
  		return 'equilateral'
  	
  	if a == b or a == c or b == c:
  		return 'isosceles'
  	
  	return 'scalene'
  
  # Error class used in part 2.  No need to change this code.
  class TriangleError(Exception):
      pass
  