[wmocjuzp] Flip inside and outside

Draw a regular polygon with all 4 edges the same length, and all angles the same: 270 degrees.

It looks like a square, but the inside and the outside have been switched.  The internal area is infinite.  The center of the polygon is outside.  Duality.

The same construction can be done for any polygon, or polyhedron, or even sphere.

Unless you can measure angles, you can't tell if you're trapped in a box! All you see are three square faces meeting at a corner.

"My God, it's full of stars!"