Copy of Flip Flop

This is a reflection puzzle. [br][br]The left sandal is reflected across a line drawn between two points in the grid to make a right sandal. [br][br]Can you move A and B to find the line of reflection?[br][br]See if you're correct by pressing the Check button.
More GeoGebra at [url]mathhombre.blogspot.com[/url]

Information: Copy of Flip Flop