diff --git a/maths/check_polygon.py b/maths/check_polygon.py
index 0e7711973..1e8dce718 100644
--- a/maths/check_polygon.py
+++ b/maths/check_polygon.py
@@ -1,7 +1,7 @@
-from typing import List
+from __future__ import annotations
 
 
-def check_polygon(nums: List) -> bool:
+def check_polygon(nums: list[float]) -> bool:
     """
     Takes list of possible side lengths and determines whether a
     two-dimensional polygon with such side lengths can exist.
@@ -14,15 +14,28 @@ def check_polygon(nums: List) -> bool:
     True
     >>> check_polygon([3, 7, 13, 2])
     False
+    >>> check_polygon([1, 4.3, 5.2, 12.2])
+    False
+    >>> nums = [3, 7, 13, 2]
+    >>> _ = check_polygon(nums) #   Run function, do not show answer in output
+    >>> nums #  Check numbers are not reordered
+    [3, 7, 13, 2]
     >>> check_polygon([])
     Traceback (most recent call last):
         ...
-    ValueError: List is invalid
+    ValueError: Monogons and Digons are not polygons in the Euclidean space
+    >>> check_polygon([-2, 5, 6])
+    Traceback (most recent call last):
+        ...
+    ValueError: All values must be greater than 0
     """
-    if not nums:
-        raise ValueError("List is invalid")
-    nums.sort()
-    return nums.pop() < sum(nums)
+    if len(nums) < 2:
+        raise ValueError("Monogons and Digons are not polygons in the Euclidean space")
+    if any(i <= 0 for i in nums):
+        raise ValueError("All values must be greater than 0")
+    copy_nums = nums.copy()
+    copy_nums.sort()
+    return copy_nums[-1] < sum(copy_nums[:-1])
 
 
 if __name__ == "__main__":