diff --git a/manim/mobject/geometry/arc.py b/manim/mobject/geometry/arc.py
index 894ca3d02b..1280d2b25d 100644
--- a/manim/mobject/geometry/arc.py
+++ b/manim/mobject/geometry/arc.py
@@ -282,8 +282,8 @@ def construct(self):
     def __init__(
         self,
         radius: float = 1.0,
-        start_angle=0,
-        angle=TAU / 4,
+        start_angle: float = 0,
+        angle: float = TAU / 4,
         num_components=9,
         arc_center=ORIGIN,
         **kwargs,
diff --git a/manim/mobject/mobject.py b/manim/mobject/mobject.py
index b9ef39af88..72382a622f 100644
--- a/manim/mobject/mobject.py
+++ b/manim/mobject/mobject.py
@@ -160,7 +160,7 @@ def add_animation_override(
             The animation type to be overridden
         override_func
             The function returning an animation replacing the default animation. It gets
-            passed the parameters given to the animnation constructor.
+            passed the parameters given to the animation constructor.
 
         Raises
         ------