number of yards in a football field
In American Football, there are 100 yards on the field (120 including the 10 yard endzones), however they don't start in the middle of the field...(except for the coin toss).
They are 100 yards on a football field. They are also an addition 10 yards in each end zone. The ball is placed in the middle (middle of the hash marks) when ever it is either turned over or down in the end zone on a kick off.