Some biplanes have different degrees of dihedral/anhedral on different wings. Most aircraft have been designed with planar wings with simple dihedral (or anhedral). As a trigonal trapezohedron, the cube is related to the hexagonal dihedral symmetry family. Denote the dihedral angles by formula 58 etc. There are 15 distinct subgroup dihedral and cyclic symmetries. The other two attached groups remain at a larger dihedral angle. The answer is just the dihedral symmetry group Dih. When downwardly inclined they are said to be at a negative dihedral angle. Factors of design other than dihedral angle also contribute to dihedral effect. This allows defining a dihedral angle that belongs to the intervl . These symmetries determine a group called the dihedral group of degree 4, denoted . The notation for the dihedral group differs in geometry and abstract algebra. An extreme example of the effect of vertical CG on dihedral effect is a paraglider. The vertical location of the CG changes the amount of dihedral effect. The purpose of dihedral effect is to contribute to stability in the roll axis.