Here's another GeoGebra Augmented Reality Construction Challenge: [br][br]Using only 2 surface equations (with domain restrictions), reconstruct the lampshade shown in the screencast below. [br][br][b]Clues:[/b][br][br]Cross sections parallel to the xy-plane are squares. [br][br]Cross sections parallel to xz-plane and cross sections parallel to yz-plane are hyperbolas with [math]a=\sqrt{2}[/math] and [math]c=\sqrt{13}[/math].