input: Write a python function to determine if two given strings are rotations of one another.
  assert are_Rotations("abc","bca") == True
  assert are_Rotations("abcdef","cdefab") == True
  assert are_Rotations("hello","olelh") == False
output: def are_Rotations(str1, str2):
      return len(str1) == len(str2) and str2 in str1 + str1