From a rectangular sheet of paper - 29.6-cm long and 8.8-cm wide you can fold a circle and the approximate its circumference. First you need to fold this strip into 16 equal parts. Bring both edges to the midline to get quarter lines. Then fold the edges to the quarter lines. By modular folding in this fashion you can easily divide the strip into 16-equal parts. Now upturn the paper such that the Mountain Folds are on the top. With the help of a scale and a used ball pen (no ink) score all the diagonals of the 16 rectangles. Crease the diagonals well. Repeat this for all the 16 rectangles. You will see that all the diagonals are Mountain Folds and all the straight lines are Valley Folds.
Finally cut off one section so that only 15 sections remain. Now on gathering the folds the strip will automatically crease itself into a circular flower shape. The model will look like a circular badge. Press all the folds well. The model will lift itself up like a spiral staircase. Now open the paper and fold it in half along the midline. Cut along the midline to get two equal and similar halves.
Take only one half and on gathering the pleats it will fold into a very neat circle. With a marker mark the circumference of the circle. On opening you will find that the circumference of the circle was actually the length of the strip with 15 sections. Here is a fun way of folding a circle from a rectangular strip of paper. This work was supported by IUCAA and Tata Trust. This film was made by Ashok Rupner
