diff --git a/exercises/practice/line-up/line_up.moon b/exercises/practice/line-up/line_up.moon
index e69de29..306a9cb 100644
--- a/exercises/practice/line-up/line_up.moon
+++ b/exercises/practice/line-up/line_up.moon
@@ -0,0 +1,4 @@
+{
+  format: (name, number) ->
+    error 'Implement me'
+}
diff --git a/exercises/practice/matrix/matrix.moon b/exercises/practice/matrix/matrix.moon
index e69de29..51a1344 100644
--- a/exercises/practice/matrix/matrix.moon
+++ b/exercises/practice/matrix/matrix.moon
@@ -0,0 +1,7 @@
+{
+  row: (str, idx) ->
+    error 'Implement me'
+
+  column: (str, idx) ->
+    error 'Implement me'
+}
diff --git a/exercises/practice/spiral-matrix/spiral_matrix.moon b/exercises/practice/spiral-matrix/spiral_matrix.moon
index e69de29..097617e 100644
--- a/exercises/practice/spiral-matrix/spiral_matrix.moon
+++ b/exercises/practice/spiral-matrix/spiral_matrix.moon
@@ -0,0 +1,4 @@
+{
+  spiral_matrix: (size) ->
+    error 'Implement me'
+}
diff --git a/exercises/practice/triangle/triangle.moon b/exercises/practice/triangle/triangle.moon
index e69de29..c6901ec 100644
--- a/exercises/practice/triangle/triangle.moon
+++ b/exercises/practice/triangle/triangle.moon
@@ -0,0 +1,10 @@
+is_equilateral = (a, b, c) ->
+  error 'Implement me'
+
+is_isosceles = (a, b, c) ->
+  error 'Implement me'
+
+is_scalene = (a, b, c) ->
+  error 'Implement me'
+
+{ :is_equilateral, :is_isosceles, :is_scalene }