To create a polygon object, you need a List or Array of Points passed during instantiation at minimum. There are 3 optional parameters: spatial reference, hasZ and hasM. Here is more detailed explaination below:
This screen shot from the help in ArcGIS explains in details what each property and syntax means. I do not need to really go into this because I assume everyone can read. The methods overview can be found here.
Example: Creating a Polygon Object From a List of Coordinates
import arcpy
# Triangle Coordinate List
#
cList = [[1,2],[2,2], [1,4]]
# Create a Point Object and Array
#
point = arcpy.Point()
array = arcpy.Array()
for feat in cList:
point.X = feat[0]
point.Y = feat[1]
array.add(point)
point = arcpy.Point()
# Close the shape
#
array.add(array.getObject(0))
# Create the polygon
#
polygon = arcpy.Polygon(array)
## DO OTHER TASKS ##