Why isn't the football placed at the last yard line where it was if a field goal is attempted? In the Eagles/Bears playoff game on 6 January 2019, the ball was run to the 11 yard line. Then they kicked it from the 29 yard line. Why?
I’m assuming that you are talking about the 29-yard field goal Chicago made to end the half.
Chicago got to the 11 yard line and decided to kick a field goal. When the field goal play starts, the ball was snapped from the 11 yard line. However, the ball is snapped back to where the kicker is located about 8 yards back, on the 19 yard line. This is considered a 29 yard field goal, because the goal posts are located at the back of end zone, 10 yards past the goal line. So when the kicker is located on the 19 yard line, it is called a 29 yard field goal.
This is a pretty typical situation. Whatever yard line the ball is on for the start of a field goal play, you can add about 17 or 18 yards to determine the distance of the field goal kick.
The typical formation of field goals are covered, but it is important to note that the NFL Rules does not require said formation.
Rule 3, Section 11 states, in part:
A Field Goal is made by a drop kick or a place kick from (a) on or behind the line on a play from scrimmage or (b) during a fair catch kick.
Therefore, one may attempt a place kick from on the line of scrimmage to convert. However, this is unlikely due to the defensive line on the line of scrimmage. I suppose an unconventional formation can to achieve this, but I cannot think of a practical way for this to occur.