Break circle_area function

drone_test/_circle_area.py

@@ -0,0 +1,13 @@
+import math
+
+def circle_area(radius: float):
+    """Calculate the area of a circle
+
+    :param radius: circle radius
+    :raises ValueError: radius is negative
+    :return: area of the circle
+    """
+    #if radius < 0:
+        #raise ValueError("Circle can't have negative radius")
+
+    return math.pi * radius ** 2