Rotation symmetry I-Fold Rotation Axis -An object that requires rotation of a full 3600 in order to restore it to its original appearance has no rotational symmetry. Since it repeats itself 1 time every 3600 it is said to have a 1-fold axis of rotational symmetry. 2-fold Rotation Axis If an object appears identical after a rotation of180°，that is twice in a360° rotation,then it is said to have a 2-fold rotation axis (360/180 = 2).Note that in these examples the axes we are referring to are imaginary lines that extend toward you perpendicular to the page or blackboard.A filled oval shape represents the point where the 2- fold rotation axis intersects the page.7 Rotation symmetry