[list=1][*]Move the teeth using the A, A', B, B' points. The unprimed points represent its original position and the primed points represent its new position.[/*][*]Drag the black and red dotted lines to help construct the center of rotation. The angle and midpoints are shown.[/*][*]Press “cycle hints” for the next construction step.[/*][*]Press "animation" to see how the tooth moves from the unprimed to primed positions.[br][/*][*]Guess the center of rotation by dragging the green point.[/*][*]Click “submit” to check your answer and check its accuracy.[/*][*]Click “reset” to hide the center of rotation and all construction hints.[/*][/list]

Created by Lewis Hicks and Priya Jamkhedkar at Portland State University.