This semester, we taught a new mathematics knowledge-translation and rotation. In fact, my understanding of these two concepts is very simple. Translation means that a figure moves to another position along a straight line without changing its shape and size. Rotation refers to rotating according to a central point, while the size and shape of the figure remain unchanged.

In life, there are many objects moving and rotating around us. First, like my mother's car driving from home to the company, my understanding is that the car has translation; The chair at home moved from the living room to my small room, which I also understand as the translation of the chair.

There's a lot of rotation. Walking in the street, I saw the windmill in the hands of children, which was spinning vigorously. My understanding is that the blades of the windmill are spinning. When the car starts, the iron support frame in the middle of the car tire is also rotating. At the door of the barber shop, the black and white advertising light box is spinning, and my understanding is also spinning. When our electric fan is turned on, there are three blades turning.

Generally speaking, it is not very complicated to feel translation and rotation, just like the judgment of rotating graphics, just remember "fixed, moving, changing, unchanged, etc." : fixed: that is, the center of rotation; Change: the position of the figure changes before and after rotation (except the rotation angle =N 360 degrees); Invariant: the size and shape of the figure are unchanged before and after rotation; Equality: that is, every point and every part of the figure rotates by an equal angle around the center of rotation. Rotation is a dynamic process.

Through this understanding, do you think translation and rotation are simple?