# Origami, Symmetry & Peace

## Symmetry in Origami

When I was about 9 years old, my uncle taught me to make the classic origami crane. See: https://www.youtube.com/watch?v=Jm7SZoCczfw (for example) To prepare, he told me to fold the square paper as shown here. The less obvious folds are made by folding each side of the square (twice) so that it coincides with one diagonal and then the other. Then, completion of the crane takes just a little practice. BTW, all of these folds are not necessary for the crane, but they help. In upper primary school, you can explore symmetry and angular measurement with this folded square. How many different polygons are there in this diagram? Use colours to help identify them. How many of each polygon are there? What angles are involved? What triangles are similar? In secondary school, a nice challenge is to find the area of each shape. For this, the student will need to apply just two geometrical theorems, Pythagoras' theorem and that corresponding sides in similar triangles are proportional, along with careful algebra. Of course, students at either level can make the crane, find out about Japan, including a girl called Sadako from Hiroshima: https://www.youtube.com/watch?v=FzIB4LkVtUE All of this can inspire the learner to reflect on peace in these troubled times ...