1, rotation refers to the transformation of mathematical graphics, which means that every point on the graphics rotates by a fixed angle around a fixed point on the plane. The figure before and after rotation is congruent, that is, the size and shape of the figure before and after rotation have not changed. In rotation, the only fixed point is the center of rotation.
2. Rotation direction-clockwise means rotating in the same direction as the clock. The opposite of clockwise rotation of an object is counterclockwise rotation, which is also related to the observation angle. For example, when viewed from directly above the North Pole, the rotation of the earth is counterclockwise, and when viewed from directly above the South Pole, the rotation of the earth is clockwise.
3. Rotation angle refers to the included angle between the rotation connecting line between the point and the center and the connecting line between the corresponding point and the rotation center after the figure is rotated. Moreover, in the process of rotating motion, three conditions should be met: irregular figures should be transformed into regular figures through rotation, with equal sides and complementary angles.
4. In a plane, rotating a figure around a point in a certain direction by an angle is called the rotation of the figure. This fixed point is called the center of rotation and the rotation angle is called the rotation angle. The rotation of a graph means that each point on the graph moves around a fixed point on the plane at a fixed angle, in which the distance from the corresponding point to the rotation center is equal.