1.The Pythagorean theorem is used in football by telling the defender how much is necessary to run.For example the ball carrier is heading for the end zone 40 yards away.The defender stands 30 yards away and needs to defend him. Pythagorean theorem states A^2 +B^2=C^2.so comparing to Pythagorean theorem these sides are the legs of the triangle. forming 90 degree angle. The distance the defender need to run is the hypotenuse. So (40^2)times(30^2)=50^2.
2. It would be important for a football player to understand the Pythagorean theorem because that way they can now the direction there running, and angle defender needs to run, the speed need to use to outrun opponent, and so that the defender can now what distance to run in a the same time it takes the ball carrier to run to the same place. This can make a difference between a touchdown or a game saving tackle.
