What is a symmetry group? Is it the same as the group of symmetries of a graphical object, like a triangle, for instance, where we talk about flips and rotations?
Yes, groups describing flips and rotations are indeed symmetry groups, but the concept is more general. The topic of groups is a rich and fascinating one with numerous applications in physics. When you take later classes in quantum physics, you will see that the bizarre procedure of angular momentum addition makes perfect sense in the context of group theory.
