diff --git a/tests/helper_classes_test.py b/tests/helper_classes_test.py
index a87f3b9..4fbb2a0 100755
--- a/tests/helper_classes_test.py
+++ b/tests/helper_classes_test.py
@@ -4,7 +4,10 @@
 import pytest
 from helpers import proto_test_case
 
-from extremitypathfinder.helper_classes import AngleRepresentation
+from extremitypathfinder import helper_classes
+from extremitypathfinder.helper_classes import AngleRepresentation, Polygon, Vertex
+
+helper_classes.origin = Vertex((-5.0, -5.0))
 
 
 class HelperClassesTest(unittest.TestCase):
@@ -52,7 +55,7 @@ def test_angle_repr(self):
         # angle %360!
         #     rep(p1) > rep(p2) <=> angle(p1) > angle(p2)
         #     rep(p1) = rep(p2) <=> angle(p1) = angle(p2)
-        # repr value in [0.0 : 4.0[
+        # repr value in [0.0 : 4.0]
 
         def value_test_fct(input):
             np_2D_coord_vector = np.array(input)
@@ -71,6 +74,84 @@ def value_test_fct(input):
 
         proto_test_case(data, value_test_fct)
 
+    def test_vertex_translation(self):
+        data = [
+            ([1.0, 1.0], [6.0, 6.0]),
+            ([0.0, 0.0], [5.0, 5.0]),
+            ([-12.0, -3.0], [-7.0, 2.0]),
+            ([-4.0, 5.0], [1.0, 10.0]),
+            ([3.0, -2.0], [8.0, 3.0]),
+        ]
+
+        def translation_test_fct(input):
+            return Vertex(input).get_coordinates_translated().tolist()
+
+        proto_test_case(data, translation_test_fct)
+
+    def test_vertex_angle_repr(self):
+        data = [
+            ([0.0, -5.0], 0.0),
+            ([-5.0, 0.0], 1.0),
+            ([-6.0, -5.0], 2.0),
+            ([-5.0, -6.0], 3.0),
+        ]
+
+        def angle_repr_test_fct(input):
+            return Vertex(input).get_angle_representation()
+
+        proto_test_case(data, angle_repr_test_fct)
+
+    def test_vertex_distance_to_origin(self):
+        data = [
+            ([0.0, 0.0], np.sqrt(50)),
+            ([-5.0, 0.0], 5.0),
+            ([0.0, -5], 5.0),
+            ([-3.0, -2.0], np.sqrt(13)),
+            ([2.0, 5.0], np.sqrt(149)),
+        ]
+
+        def dist_to_origin_test_fct(input):
+            return Vertex(input).get_distance_to_origin()
+
+        proto_test_case(data, dist_to_origin_test_fct)
+
+    def test_polygon_bad_input(self):
+        with pytest.raises(ValueError) as err:
+            Polygon([(0, 0), (1, 1)], is_hole=False)
+        assert "not a valid polygon" in str(err)
+
+    def test_polygon_extremities(self):
+        data = [
+            (
+                [
+                    (0, 0),
+                    (10, 0),
+                    (9, 5),
+                    (10, 10),
+                    (0, 10),
+                ],
+                [(9, 5)],
+            ),
+            (
+                [
+                    (0, 0),
+                    (-2, -2),
+                    (-3, -2.5),
+                    (-3, -4),
+                    (2, -3),
+                    (1, 2.5),
+                    (0, -1),
+                ],
+                [(0, -1), (-2, -2)],
+            ),
+        ]
+
+        def find_extremities_test_fct(input):
+            extremities = Polygon(input, is_hole=False).extremities
+            return [tuple(e.coordinates) for e in extremities]
+
+        proto_test_case(data, find_extremities_test_fct)
+
 
 if __name__ == "__main__":
     suite = unittest.TestLoader().loadTestsFromTestCase(HelperClassesTest)