diff --git a/tests/shapes/lines/bases.py b/tests/shapes/lines/bases.py
index 597ff29a..1dfe2e2a 100644
--- a/tests/shapes/lines/bases.py
+++ b/tests/shapes/lines/bases.py
@@ -91,7 +91,8 @@ def test_distance(self, shape, test_point, expected_distance):
         Test the distance() method parametrized by distance_test_cases
         (see conftest.py).
         """
-        assert pytest.approx(shape.distance(*test_point)) == expected_distance
+        actual_distance = shape.distance(*test_point)
+        assert pytest.approx(actual_distance) == expected_distance
 
     def test_lines_form_polygon(self, shape):
         """Test that the lines form a polygon."""
diff --git a/tests/shapes/lines/test_diamond.py b/tests/shapes/lines/test_diamond.py
index 4eecad38..a0b112a7 100644
--- a/tests/shapes/lines/test_diamond.py
+++ b/tests/shapes/lines/test_diamond.py
@@ -12,7 +12,14 @@ class TestDiamond(PolygonsLineModuleTestBase):
     """Test the Diamond class."""
 
     shape_name = 'diamond'
-    distance_test_cases = (((20, 50), 0.0), ((30, 60), 2.773501))
+    distance_test_cases = (
+        ((20, 50), 0),
+        ((20, 77), 0),
+        ((11, 63.5), 0),
+        ((29, 63.5), 0),
+        ((30, 63.5), 1),
+        ((30, 60), 2.773501),
+    )
     expected_line_count = 4
 
     def test_slopes(self, slopes):
diff --git a/tests/shapes/lines/test_rectangle.py b/tests/shapes/lines/test_rectangle.py
index 64cf26d3..ed0ce318 100644
--- a/tests/shapes/lines/test_rectangle.py
+++ b/tests/shapes/lines/test_rectangle.py
@@ -12,7 +12,14 @@ class TestRectangle(PolygonsLineModuleTestBase):
     """Test the Rectangle class."""
 
     shape_name = 'rectangle'
-    distance_test_cases = (((20, 50), 0.0), ((30, 60), 2.0))
+    distance_test_cases = (
+        ((12, 60), 0),
+        ((28, 60), 0),
+        ((20, 50), 0),
+        ((20, 74), 0),
+        ((20, 75), 1),
+        ((30, 80), 6.324555320336759),
+    )
     expected_line_count = 4
 
     def test_slopes(self, slopes):