How do you draw an x in a box without picking up your pencil or overlapping?

It's a trick question, one that is from a famous puzzle.

It is the one that spawned the phrase, think "outside the box."

The puzzle is this.

Nine dots are arranged so that they form a square, three rows of

three dots, equally spaced.

Now, draw four straight lines that run through all nine dots,

all without lifting your pencil from the paper.

Most folks will feel the need to constrain their lines to the imaginary boundaries

that define the "box" although no such rule was stated.

By drawing far "outside the box," the lines are easily executed.