Answer based on context:

The Giants flew to Ford Field for a Week 11 intraconference duel with the Detroit Lions.  In the first quarter, New York took the early lead as kicker Lawrence Tynes made a 28-yard field goal for the only score of the period.  In the second quarter, the Giants increased their lead as QB Eli Manning completed a 10-yard TD pass to RB Brandon Jacobs for the only score of the period. In the third quarter, the Lions got on the board as kicker Jason Hanson made a 42-yard field goal.  New York would reply with Tynes kicking a 46-yard field goal.  In the fourth quarter, the Giants improved their lead as Tynes made a 20-yard field goal.  Detroit's QB Jon Kitna completed a 35-yard TD pass to WR Calvin Johnson. LB Mathias Kiwanuka suffered a broken left fibula, ending his season.

How many yards was the shortest field goal of the game?
20