Single cut triangle | English

Here is a triangle - a scalene triangle where none of the three sides are equal. The triangle is drawn on a card sheet. Now can you remove the triangle from the sheet with JUST ONE SINGLE CUT? We will need an A-4 sheet, pen, scale and scissors. First draw any scalene triangle with all 3 sides having different lengths. So, all three angles will also be different. First fold the 3 sides of the triangle. Then place one side on the other and fold to divide the angle in two equal parts. This crease is called the angle bisector. Fold the angle bisector of all three angles. All the three angle bisectors will meet at a point which is called as the IN-CENTER. Now draw all the 3 angle bisector lines with a scale and pen. Now fold along all the 3 angle bisectors. This way you will be dividing the triangle in 3 parts with petals. Then fold so that the bases of the triangles meet. It will appear as if you had drawn perpendiculars from the IN CENTER to each side of the triangle. The distance from the IN CENTER to each side will be the same. So, all the 3 petals will fold along the same base. And now with one SINGLE CUT you can remove the triangle from the sheet of paper. You can extend this to cut not just Triangles but any POLYGON using this method.
This work is supported by IUCAA (www.iucaa.ernet.in) and TATA Trust (www.tata.com/aboutus/sub_index/Tata-trusts)
Credits:,Ashok Rupner, Manish Jain, Pradnya Pujari, Shivaji Mane, Jyoti Hiremath, Arvind Gupta, Vidula Mhaiskar TATA Trust: Education is one of the key focus areas for Tata Trusts, aiming towards enabling access of quality education to the underprivileged population in India. To facilitate quality in teaching and learning of Science education through workshops, capacity building and resource creation, Tata Trusts have been supporting Muktangan Vigyan Shodhika (MVS), IUCAA's Children’s Science Centre, since inception. To know more about other initiatives of Tata Trusts, please visit www.tatatrusts.org