Origami is so delicate @ Just for design Ordinary origami 1 As shown in the figure, the area where two rectangular bars intersect A parallelogram or rectangle (when two rectangles are perpendicular) We know that a parallelogram or a rectangle has two diagonals Choose a diagonal line and divide the two rectangles into two parts. Can make two kinds of origami in opposite directions How to do it? Edit the vertex and move the vertex on the right to the intersection of the diagonal and rectangle Then move the vertex of the other rectangle on the right as well. Origami in other directions is similar. Only the diagonal line chosen is different from the Origami direction. Do you find the difference between these eight kinds of origami? Ordinary origami 2 As shown in the figure, the area where two rectangular bars intersect It's an irregular shape. 1 1 2 2 Assuming that rectangular bar 1 remains unchanged Move rectangular bar 2 so that it shares a vertex with the lower right corner of rectangular bar 1 1 11 2 2 Extend rectangular strip 2, the top right corner vertex coincides with rectangular strip 1. So there's a diagonal line. 1 1 2 2 Move all the vertices on the right side of the diagonal line to The intersection of diagonal line and corresponding rectangle PS: When skilled, dotted lines can be discarded. That's all right. The line at the corner is actually the diagonal line after the intersection of two rectangular strips. In-depth study We all know that. Faces are made up of innumerable lines. Lines are made up of innumerable points. From the point of view, go back and look at Origami From the angle of a line: connect points with a straight line • • Total length of orange line = total length of black line The orange and black lines of different folds are not equal in length What if the two lines of different folds are equal in length? Duplicate the orange line to get the black line Then move the black line • We will find that all points on the black line are obtained from the corresponding points on the orange line through the same displacement. Make three folds as shown in the figure.