You can put this solution on YOUR website!
First, a hexagon is any six-sided polygon. A hexagon may have no lines of symmetry at all.
But, I expect that you meant to say..."regular hexagon" which is a six-sided polygon all of whose sides are of equal length, right?
A regular hexagon has six lines of symmetry.
You can easily see these by connecting the six vertices, this gives you three lines of symmetry. Then connecting the bisectors of the six sides for another three lines of symmetry.