diff --git a/exercises/triangle/.version b/exercises/triangle/.version
new file mode 100644
index 0000000000..56a6051ca2
--- /dev/null
+++ b/exercises/triangle/.version
@@ -0,0 +1 @@
+1
\ No newline at end of file
diff --git a/exercises/triangle/example.rb b/exercises/triangle/example.rb
index c14012360b..65cf463f08 100644
--- a/exercises/triangle/example.rb
+++ b/exercises/triangle/example.rb
@@ -1,44 +1,37 @@
-class TriangleError < RuntimeError
+module BookKeeping
+  VERSION = 1
 end
 
 class Triangle
-  attr_reader :a, :b, :c
-  def initialize(a, b, c)
-    @a = a
-    @b = b
-    @c = c
-  end
+  attr_reader :sides
 
-  def kind
-    fail TriangleError if illegal?
-    if equilateral?
-      :equilateral
-    elsif isosceles?
-      :isosceles
-    else
-      :scalene
+  def initialize(sides)
+    @sides = sides
+    if illegal?
+      @sides = []
     end
   end
 
-  private
-
-  def sides
-    @sides ||= [a, b, c]
-  end
-
   def equilateral?
     sides.uniq.size == 1
   end
 
   def isosceles?
-    sides.uniq.size == 2
+    sides.uniq.size.between?(1, 2)
   end
 
+  def scalene?
+    sides.uniq.size == 3
+  end
+
+  private
+
   def illegal?
     impossible_length_side? || violates_inequality?
   end
 
   def violates_inequality?
+    a, b, c = sides
     a + b <= c || a + c <= b || b + c <= a
   end
 
diff --git a/exercises/triangle/example.tt b/exercises/triangle/example.tt
new file mode 100644
index 0000000000..7a4cac18a9
--- /dev/null
+++ b/exercises/triangle/example.tt
@@ -0,0 +1,20 @@
+#!/usr/bin/env ruby
+gem 'minitest', '>= 5.0.0'
+require 'minitest/autorun'
+require_relative 'triangle'
+
+# Test data version:
+# <%= sha1 %>
+class TriangleTest < Minitest::Test<% test_cases.each do |test_case| %>
+  def <%= test_case.test_name %>
+    <%= test_case.skipped %>
+    <%= test_case.workload %>
+  end
+<% end %>
+<%= IO.read(XRUBY_LIB + '/bookkeeping.md') %>
+  def test_bookkeeping
+    skip
+    assert_equal <%= version.next %>, BookKeeping::VERSION
+  end
+end
+
diff --git a/exercises/triangle/triangle_test.rb b/exercises/triangle/triangle_test.rb
index 41ce62ec24..b5277fe085 100755
--- a/exercises/triangle/triangle_test.rb
+++ b/exercises/triangle/triangle_test.rb
@@ -3,91 +3,131 @@
 require 'minitest/autorun'
 require_relative 'triangle'
 
+# Test data version:
+# b806246
 class TriangleTest < Minitest::Test
-  def test_equilateral_triangles_have_equal_sides
-    assert_equal :equilateral, Triangle.new(2, 2, 2).kind
+  def test_triangle_is_equilateral_if_all_sides_are_equal
+    # skip
+    triangle = Triangle.new([2, 2, 2])
+    assert triangle.equilateral?, "Expected 'true', triangle is equilateral."
   end
 
-  def test_larger_equilateral_triangles_also_have_equal_sides
+  def test_triangle_is_not_equilateral_if_any_side_is_unequal
     skip
-    assert_equal :equilateral, Triangle.new(10, 10, 10).kind
+    triangle = Triangle.new([2, 3, 2])
+    refute triangle.equilateral?, "Expected 'false', triangle is not equilateral."
   end
 
-  def test_isosceles_triangles_have_last_two_sides_equal
+  def test_triangle_is_not_equilateral_if_no_sides_are_equal
     skip
-    assert_equal :isosceles, Triangle.new(3, 4, 4).kind
+    triangle = Triangle.new([5, 4, 6])
+    refute triangle.equilateral?, "Expected 'false', triangle is not equilateral."
   end
 
-  def test_isosceles_triangles_have_first_and_last_sides_equal
+  def test_all_zero_sides_are_illegal_so_the_triangle_is_not_equilateral
     skip
-    assert_equal :isosceles, Triangle.new(4, 3, 4).kind
+    triangle = Triangle.new([0, 0, 0])
+    refute triangle.equilateral?, "Expected 'false', triangle is not equilateral."
   end
 
-  def test_isosceles_triangles_have_two_first_sides_equal
+  def test_equilateral_triangle_sides_may_be_floats
     skip
-    assert_equal :isosceles, Triangle.new(4, 4, 3).kind
+    triangle = Triangle.new([0.5, 0.5, 0.5])
+    assert triangle.equilateral?, "Expected 'true', triangle is equilateral."
   end
 
-  def test_isosceles_triangles_have_in_fact_exactly_two_sides_equal
+  def test_triangle_is_isosceles_if_last_two_sides_are_equal
     skip
-    assert_equal :isosceles, Triangle.new(10, 10, 2).kind
+    triangle = Triangle.new([3, 4, 4])
+    assert triangle.isosceles?, "Expected 'true', triangle is isosceles."
   end
 
-  def test_isosceles_triangles_have_unequal_side_larger_than_equal_sides
+  def test_triangle_is_isosceles_if_first_two_sides_are_equal
     skip
-    assert_equal :isosceles, Triangle.new(4, 7, 4).kind
+    triangle = Triangle.new([4, 4, 3])
+    assert triangle.isosceles?, "Expected 'true', triangle is isosceles."
   end
 
-  def test_scalene_triangles_have_no_equal_sides
+  def test_triangle_is_isosceles_if_first_and_last_sides_are_equal
     skip
-    assert_equal :scalene, Triangle.new(3, 4, 5).kind
+    triangle = Triangle.new([4, 3, 4])
+    assert triangle.isosceles?, "Expected 'true', triangle is isosceles."
   end
 
-  def test_2a_equals_b_plus_c_looks_like_equilateral_but_is_not
+  def test_equilateral_triangles_are_also_isosceles
     skip
-    assert_equal :scalene, Triangle.new(5, 4, 6).kind
+    triangle = Triangle.new([4, 4, 4])
+    assert triangle.isosceles?, "Expected 'true', triangle is isosceles."
   end
 
-  def test_scalene_triangles_have_no_equal_sides_at_a_larger_scale_too
+  def test_triangle_is_not_isosceles_if_no_sides_are_equal
     skip
-    assert_equal :scalene, Triangle.new(10, 11, 12).kind
+    triangle = Triangle.new([2, 3, 4])
+    refute triangle.isosceles?, "Expected 'false', triangle is not isosceles."
   end
 
-  def test_scalene_triangles_have_no_equal_sides_in_descending_order_either
+  def test_sides_that_violate_triangle_inequality_are_not_isosceles_even_if_two_are_equal
     skip
-    assert_equal :scalene, Triangle.new(5, 4, 2).kind
+    triangle = Triangle.new([1, 1, 3])
+    refute triangle.isosceles?, "Expected 'false', triangle is not isosceles."
   end
 
-  def test_very_small_triangles_are_legal
+  def test_isosceles_triangle_sides_may_be_floats
     skip
-    assert_equal :scalene, Triangle.new(0.4, 0.6, 0.3).kind
+    triangle = Triangle.new([0.5, 0.4, 0.5])
+    assert triangle.isosceles?, "Expected 'true', triangle is isosceles."
   end
 
-  def test_triangles_with_no_size_are_illegal
+  def test_triangle_is_scalene_if_no_sides_are_equal
     skip
-    assert_raises(TriangleError) do
-      Triangle.new(0, 0, 0).kind
-    end
+    triangle = Triangle.new([5, 4, 6])
+    assert triangle.scalene?, "Expected 'true', triangle is scalene."
   end
 
-  def test_triangles_violating_triangle_inequality_are_illegal
+  def test_triangle_is_not_scalene_if_all_sides_are_equal
     skip
-    assert_raises(TriangleError) do
-      Triangle.new(1, 1, 3).kind
-    end
+    triangle = Triangle.new([4, 4, 4])
+    refute triangle.scalene?, "Expected 'false', triangle is not scalene."
   end
 
-  def test_triangles_violating_triangle_inequality_are_illegal_2
+  def test_triangle_is_not_scalene_if_two_sides_are_equal
     skip
-    assert_raises(TriangleError) do
-      Triangle.new(7, 3, 2).kind
-    end
+    triangle = Triangle.new([4, 4, 3])
+    refute triangle.scalene?, "Expected 'false', triangle is not scalene."
   end
 
-  def test_triangles_violating_triangle_inequality_are_illegal_3
+  def test_sides_that_violate_triangle_inequality_are_not_scalene_even_if_they_are_all_different
     skip
-    assert_raises(TriangleError) do
-      Triangle.new(1, 3, 1).kind
-    end
+    triangle = Triangle.new([7, 3, 2])
+    refute triangle.scalene?, "Expected 'false', triangle is not scalene."
+  end
+
+  def test_scalene_triangle_sides_may_be_floats
+    skip
+    triangle = Triangle.new([0.5, 0.4, 0.6])
+    assert triangle.scalene?, "Expected 'true', triangle is scalene."
+  end
+
+  # Problems in exercism evolve over time, as we find better ways to ask
+  # questions.
+  # The version number refers to the version of the problem you solved,
+  # not your solution.
+  #
+  # Define a constant named VERSION inside of the top level BookKeeping
+  # module, which may be placed near the end of your file.
+  #
+  # In your file, it will look like this:
+  #
+  # module BookKeeping
+  #   VERSION = 1 # Where the version number matches the one in the test.
+  # end
+  #
+  # If you are curious, read more about constants on RubyDoc:
+  # http://ruby-doc.org/docs/ruby-doc-bundle/UsersGuide/rg/constants.html
+
+  def test_bookkeeping
+    skip
+    assert_equal 1, BookKeeping::VERSION
   end
 end
+
diff --git a/lib/triangle_cases.rb b/lib/triangle_cases.rb
new file mode 100644
index 0000000000..09afe6a307
--- /dev/null
+++ b/lib/triangle_cases.rb
@@ -0,0 +1,51 @@
+class TriangleCase < OpenStruct
+  def test_name
+    initial = description.downcase
+    replaced = initial.gsub(/(true|false)/, expected_type)
+    if initial.eql?(replaced) && !initial.include?(triangle)
+      replaced = triangle + ' triangle ' + initial
+    end
+    'test_%s' % replaced.tr_s(', -', '_')
+  end
+
+  def workload
+    [
+      "triangle = Triangle.new(#{sides})",
+      indent("#{assert_or_refute} triangle.#{triangle}?, #{failure_message}")
+    ].join("\n")
+  end
+
+  def indent(line)
+    ' ' * 4 + line
+  end
+
+  def assert_or_refute
+    expected ? 'assert' : 'refute'
+  end
+
+  def failure_message
+    %Q("Expected '#{expected}', #{expected_type}.")
+  end
+
+  def expected_type
+    "triangle is #{expected ? '' : 'not '}#{triangle}"
+  end
+
+  def skipped
+    index.zero? ? '# skip' : 'skip'
+  end
+end
+
+TriangleCases = proc do |data|
+  i = 0
+  cases = []
+  data = JSON.parse(data).select { |key, value| key.to_s.match(/[^#]+/) }
+  data.keys.each do |triangle|
+    data[triangle]['cases'].each do |row|
+      row = row.merge(row.merge('index' => i, 'triangle' => triangle))
+      cases << TriangleCase.new(row)
+      i += 1
+    end
+  end
+  cases
+end