The 49ers stayed at home for a Week 3 contest against the Philadelphia Eagles. From the get-go, the Niners trailed as QB Donovan McNabb managed to complete two TD passes to RB Brian Westbrook (a 4-yard pass) and WR L.J. Smith (a 1-yard pass) in the first quarter. In the second quarter, San Francisco would get on the board with Kicker Joe Nedney completing a 48-yard field goal, but Philadelphia would strike hard, as RB Brian Westbrook ran 71 yards for a touchdown and Kicker David Akers completed a 21-yard field goal. In the third quarter, both sides managed to get themselves a touchdown. Eagles DT Mike Patterson returned a 49ers fumble 98 yards for a touchdown, while the Niners' rookie RB Michael Robinson got a 1-yard TD run. In the fourth quarter, San Francisco tried to come back with Robinson getting another 1-yard TD run.  However, the Eagles got an 8-yard TD run by Westbrook.  The Niners would get one more score, as QB Alex Smith completed a TE Eric Johnson, but that would as far as they would get, as the 49ers fell to 1-2 on the year.
Question: How many yards was the shortest field goal?
Answer: 21