Add surface area class (#2183)

* add surface area class

* add new line to end of file

* move surface area class into area class

* add missing import

* added pi import

* fix typo

* added blank line

* fixed more import issues

* comment fix

* comment fixes

maths/area.py

@@ -1,8 +1,34 @@
 """
 Find the area of various geometric shapes
 """
+from math import pi
+from typing import Union
 
-import math
+
+def surface_area_cube(side_length: Union[int, float]) -> float:
+    """
+    Calculate the Surface Area of a Cube.
+
+    >>> surface_area_cube(1)
+    6
+    >>> surface_area_cube(3)
+    54
+    """
+    return 6 * pow(side_length, 2)
+
+
+def surface_area_sphere(radius: float) -> float:
+    """
+    Calculate the Surface Area of a Sphere.
+    Wikipedia reference: https://en.wikipedia.org/wiki/Sphere
+    :return 4 * pi * r^2
+
+    >>> surface_area_sphere(5)
+    314.1592653589793
+    >>> surface_area_sphere(1)
+    12.566370614359172
+    """
+    return 4 * pi * pow(radius, 2)
 
 
 def area_rectangle(base, height):
@@ -62,7 +88,7 @@ def area_circle(radius):
     >> area_circle(20)
     1256.6370614359173
     """
-    return math.pi * radius * radius
+    return pi * radius * radius
 
 
 def main():
@@ -73,6 +99,9 @@ def main():
     print(f"Parallelogram: {area_parallelogram(10, 20)=}")
     print(f"Trapezium: {area_trapezium(10, 20, 30)=}")
     print(f"Circle: {area_circle(20)=}")
+    print("Surface Areas of various geometric shapes: \n")
+    print(f"Cube: {surface_area_cube(20)=}")
+    print(f"Sphere: {surface_area_sphere(20)=}")
 
 
 if __name__ == "__main__":