Any rotation can be composed from two axial symmetries with axes intersecting in the center of rotation, the angle between which is half the angle of the rotation, and vice versa, composition of axial symmetries in two intersecting lines is equal to a rotation.
Task: Triangle ArBrCr is an image of triangle ABC by the rotation given by the center S and the angle α, see figure below. Revolving the axes o1, o2 around their common point S by dragging points P and Q, merge the yellow triangle A2B2C2 with ArBrCr.