This applet can be used to model the spatial relationship between two football players (i.e., the ball carrier and the defender.) This applet is intended to introduce students to the Pythagorean Theorem. After adjusting the sliders to set the positions of the football players, students can calculate the distance that the defender would have to travel in order to tackle the carrier. Students input their solutions (to the nearest hundredth) and a message will let them know whether their response was "correct" or whether they need to "try again." An extension to this applet would be to assign the carrier a velocity, and then have students determine how fast the defender would have to run in order to make the tackle.