It makes us think there is new information or a follow-up question and we spend time opening the thread. Simply click on the Thank button at the bottom left-hand corner of any post you find helpful. I agree with Mike.
Symmetry comes from a Greek word meaning 'to measure together' and is widely used in the study of geometry. Mathematically, symmetry means that one shape becomes exactly like another when you move it in some way: turn, flip or slide.
Symmetries preserve distances, angles, sizes, and shapes. 1  For example, rotation by 90 degrees about a fixed point is an example of a plane symmetry. 2  Another basic type of symmetry is a reflection. 3  A third type of symmetry is translation. 4  The fourth (and last) type of symmetry is a glide reflection.