Distance in the Coordinate Plane (Quick Discovery)

The goal here is to find the distance between any two points in the coordinate plane. This applet was designed to help you discover how this task is possible. Before clicking the "Show Hint" checkbox in the applet below, take a couple of minutes to see if you can figure out a way to calculate the distance between points A & B in the applet below. Points A & B are moveable, by the way. If you're totally stuck after a few minutes, click the "Show Hint" checkbox. What appears should trigger your memory and remind you of a previous important concept you've learned once before.