Hexagon has no degrees of freedom but can seen as directed edges. Hexagons of symmetry g2, i4, and r12, as parallelogons can tessellate the Euclidean plane by translation. Other hexagon shapes can tile the plane with different orientations. The 6 roots of the simple Lie group , represented by a Dynkin diagram , are in a regular hexagonal pattern. The two simple roots have a 120° angle between them. The 12 roots of the Exceptional Lie group G2, represented by a Dynkin diagram are also in a hexagonal pattern. The two simple roots of two lengths have a 150° angle between
Magic hexagon can be called a T-hexagon and it has many more properties than the hexagon of hexagons. As with the above, the rows of triangles run in three directions and there are 24 triangles in a T-hexagon of order 2. In general, a T-hexagon of order "n" has formula_10 triangles. The sum of all these numbers is given by: If we try to construct a magic T-hexagon of side "n", we have to choose "n" to be even, because there are rows so the sum in each row must be For this to be an integer, "n" has to be even.