Although this is a Prezi it was still quite useful and had food information. This Prezi explains basic geometry, reflections, translations, rotation, and symmetry in ballet. When doing a pirouette a dancer is using rotation. The center of rotation is placed either on the ball of the foot or on the toes, depending on whether or not the dancer is wearing pointe shoes. If a dancer is slouching or sitting on one hip then it won’t be a proper reflection and they won’t be symmetrical.
This was useful because it had a lot of pictures and videos to go along with the information. It also had good examples and everything was explained very clearly. I didn’t have any other resource that talked about rotations and translations, so this slideshow was very useful.