File talk:Ruled hyperboloid.jpg

Are you sure that this is a hyperboloid of one sheet? The description in the original page seems incorrect. Indeed, it looks suspiciously similar to the "quartic surface with double line" model (number 52 in that page). Check carefully the wires and how they cross, and compare with those of a true doubly ruled hyperboloid (number 68). All the best, --Jorge Stolfi (talk) 15:25, 26 June 2009 (UTC)