As shown in the figure, the plane for finding the midpoint of the material is divided into three parts, one of which is folded up and the other is folded back.
As shown in the figure, flatten the material and then fold it in half.
Cut off the parts marked with diagonal lines.
Symmetry axis paper cutting is completed.
Symmetric figures, mathematical terms, have many classifications, such as rotational symmetric figures, axisymmetric figures, central symmetric figures and so on.
If a graph rotates 180 degrees around a certain point, and the rotated graph can completely coincide with the original graph, then this graph is called a centrosymmetric graph. And this center point is called the center symmetry point.
The line segments connected by each pair of symmetrical points on the central symmetric graph are equally divided by the symmetric center.
In a plane, if a graph rotates 180 degrees around a certain point, and the rotated graph can completely coincide with another graph, it is said that the two graphs form central symmetry. This point is called the symmetry center.
Common central symmetric figures are rectangle, diamond, square, parallelogram, circle and some irregular figures.