After a 2-0 start, the Eagles traveled to take on the Cardinals.  The Cards struck first in the first quarter with Jay Feely's 47-yard field goal for a 3-0 lead followed by Kevin Kolb finding Michael Floyd on an 8-yard touchdown pass for a 10-0 lead.  The Cards would increase their lead in the 2nd quarter with Kolb finding Larry Fitzgerald on a 37-yard pass and then James Sanders recovering a fumble and returning it 98 yards for a touchdown for leads of 17-0 and then a 24-0 halftime lead.  The Eagles managed to get on the board in the 3rd quarter with Alex Henery's 2 field goals from 36 and 40 yards out to decrease the lead to 24-3 and then 24-6.  In the 4th quarter the Cardinals ended up getting their only points of the 2nd half with Feely's 27-yard field goal to end the game with a final score of 27-6.
Question: How many points did the Cardinals win by?
Answer: 21