Hint: In order to get the answer to this problem you need to draw the closed diagram which has six equal sides. Doing this you will get the right answer. The diagram of hexagon can be drawn as:
Complete step-by-step answer:
A regular hexagon with six equal sides has six lines of symmetry.
For all regular polygons, the number of lines of symmetry is equal to the number of sides. That is an equilateral triangle has 3 lines of symmetry, a square has 4 lines of symmetry, similarly a regular hexagon has 6 lines of symmetry.
The answer is 6.
Note: In this question you need to know that a hexagon is a six-sided polygon or 6-gon. The total of the internal angles of any simple hexagon is 720 degrees. Knowing this you will get the right answer.