Ellipse perimeter calculation

Updated the perimeter calculation for Ellipse using Ramanujan's approximation, which is more accurate

Author: avyukth-fll

geometry/geometry.py

@@ -103,9 +103,11 @@ def area(self) -> float:
     def perimeter(self) -> float:
         """
         >>> Ellipse(5, 10).perimeter
-        47.12388980384689
+        48.44222344723793
         """
-        return math.pi * (self.major_radius + self.minor_radius)
+        a, b = self.major_radius, self.minor_radius
+        #uses ramanujans approximation
+        return math.pi * (3*(a + b) - ((3*a + b)*(a + 3*b))**0.5)
 
 
 class Circle(Ellipse):