I came across this puzzle a few days back and I must confess that it got me stumped for a while.But finally,I was able to solve it.Here's the puzzle:

Given four wine glasses such that each has same size and shape.You need to arrange them so that the center of the foot of anyone is equidistant from all the rest.

Here's the solution:
Place 3 of the wine glasses on the table so as to form an Equilateral triangle, each side being equal to the height of a single glass. Then place the 4th glass upside down in the middle. Got it?