triangle.rb

# 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.rb
# and
#   about_triangle_project_2.rb
#
def triangle(a, b, c)
  values = [a, b, c].sort
  a, b, c = values
  raise TriangleError if values.min <= 0
  raise TriangleError if a + b <= c

  return :equilateral if a == b && b == c
  return :isosceles if a == b || b == c || c == a
  return :scalene if a != b && b != c
end

# another clear solution

# def triangle(a, b, c)
#   raise TriangleError if [a,b,c].min <= 0
#   x, y, z = [a,b,c].sort
#   raise TriangleError if x + y <= z
#   [:equilateral,:isosceles,:scalene].fetch([a,b,c].uniq.size - 1)
# end

# Error class used in part 2.  No need to change this code.
class TriangleError < StandardError
end