#!/usr/bin/env python

# -*- coding: utf-8 -*-

# Triangle Project Code.

# triangle(a, b, c) 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):

# DELETE 'PASS' AND WRITE THIS CODE

if a <= 0 or b <= 0 or c <= 0: raise TriangleError()

elif a >= b + c or b >= a + c or c >= a + b: raise TriangleError()

elif a == b and b == c: return 'equilateral'

elif a == b or b == c or a == c: return 'isosceles'

else: return 'scalene'

# Error class used in part 2. No need to change this code.

class TriangleError(StandardError):

pass