Answer:
ANY NUMBER THAT HAS A X BEHIND IT..
Examples
1x
7x
15803x
104762836297x
A square rotated about its center by 360º maps onto itself at 4 different angles of rotation. You can reflect a square onto itself across 4 different lines of reflection.
60 miles in 1 hour (divide the miles by the hours)
$810 !! hope this helps :)
