1. Definition of axisymmetric figure: If a figure is folded in half along a straight line, the parts on both sides of the straight line can overlap each other.

Then this figure is called an axisymmetric figure, and this straight line is its axis of symmetry. When two graphs overlap, the point where they overlap each other is called.

Make corresponding points. Angles that coincide with each other are called corresponding angles. Line segments that coincide with each other are called corresponding line segments.

2. Features of axisymmetric graphics: When folded in half along the axis of symmetry, the corresponding points, corresponding line segments and corresponding angles can overlap.

3. The essence of axisymmetric figure: the distance between corresponding points is equal to the axis of symmetry.

4. Definition of rotation: The graphic transformation in which a graphic rotates by an angle around a point is called rotation.

5. The essence of graphic rotation: when a graphic rotates around a certain point, the corresponding points and line segments in the graphic also rotate.

Correspondence, the distance from the corresponding point to the rotation point is equal, and the corresponding angle is equal.

6. Features of graphic rotation: After graphic rotation, the shape and size have not changed, but the position and direction have changed.

7. Rotation should define three elements: center point, direction and rotation angle.

8. In the process of rotation, the rotation center point always remains the same.

9. In a plane, a graphic moves a certain distance along a certain direction, and such graphic movement becomes translation. Translation will only change

The position of the graph has changed, but the size of the graph remains the same.

10. Basic methods of graphic design: Simple and beautiful patterns can be designed by translation, rotation and symmetry.

1 1. The difference between axisymmetric graphs and axisymmetric graphs: