Riddle

[lkelly2477]

How can you arrange four ordinary wineglasses on an ordinary table so that "foot" (center of the bottom of the stem) of each is the same distance from all the others?

[jeisensei]

How can you arrange four ordinary wineglasses on an ordinary table so that "foot" (center of the bottom of the stem) of each is the same distance from all the others?

This is a hard one. Maybe it has something to do with triangles and turning one upside down?

[lkelly2477]

You're on the right track.

[Pitarou]

The only way to arrange four equidistant objects is as a tetrahedron (like a pyramid, but with a triangular base). You can do that with the feet of the wine glasses by placing three of them on the table in triangular formation, and then placing the fourth one upside-down in the centre of the triangle.