The paper ratio is between 1:2.4 and 1:3, and the remaining edge of A4 paper after cutting into a square is just right
The red dashed line is the valley fold
The solid black line is the peak fold
The green line is Auxiliary lines
01. Take the first square
02. Post diagonally Take the sides of the square
03. Take another diagonal line
04. Half the first square
05 .Half the long end of the entire paper
06.1/4 Long head, be careful not to reach the top
07. Fold the corner toward the center point of the first square
