Hexagons are polygons with six sides (or edges) and six angles (or vertices). They are classified as regular or irregular, as well as convex or concave.
Like all polygons, hexagons must be closed and have no curved lines. Regular hexagons have six equal sides, with all the interior angles at 120 degrees and exterior angles of 60 degrees. They resemble the shape of honeycomb cells.
Irregular hexagons may have various shapes, as long as they still have six straight edges and six angles in a closed shape. If any internal angles are greater than 180 degrees (pointing inward), it is considered a concave hexagon. Otherwise, the shapes are considered convex.