Mathematics and Origami- Once the folding line is obtained, it makes no difference to fold the point over the edge
or viceversa. - Corner E can be considered as an internal point of a larger rectangle.
Therefore, the result is a series of straight lines whose envelope is a parabola.
1.2.6 FOLD A PAPER EDGE over two inner points.
There may be a unique or a double solution; the edge and the straight line determined by
those two points are symmetrical with respect to the folding line. In the second case both
creases are perpendicular: bisectors of two supplementary angles.1.2.7 PERPENDICULAR BISECTOR OF A SEGMENT.
Let two points in a piece of paper. If we fold it in such a way that one of the points will lay
over the other, the folding line will be the perpendicular bisector of the segment determined
by both points. By so doing we can see that the points are symmetrical with respect to the
folding line, which is the characteristic of a perpendicular bisector. It ́s advisable to mark
heavily both points in order to let them coincide by transparency.1.2.8 BISECTOR OF THE ANGLE FORMED BY TWO STRAIGHT LINES.
1- The bisector of edges ed is the folding line f.
2- c (valley) is the bisector of lines ab (mountain).
3- g (valley) is the mean parallel of edges hi.
4- j (valley) is the mean parallel of lk (mountains).aa