The name of a shape depends on how many sides it has. A hexagon is a polygon that has six sides. Remember the "x" in "six" and "hex," and you'll be fine.
Many of our words in science and math hearken back to the Greek, and hexagon is no exception. The idea of a six-sided figure comes from the Greek hexágōnon, with gonia meaning "angle," which makes sense, as a hexagon not only has six sides, but six angles, or vertices. There are various types of hexagons, including the "regular hexagon" (where all the sides and angles are equal to each other) and the "irregular hexagon" (which has unequal angles and sides).
