How to make an equilateral triangle from a square

Triangles are the strongest shapes in the world, due to the fact that with 3 lengths of sides, only one triangle can be made. This Instructable will teach you how to make a paper equilateral triangle out of a square without any tools. I was taught how to do this a while back but I have not seen any Instructables on how to do this.
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Step 1: Start with a square.


  • A piece of square paper


  • Scissors (optional)
  • Pencil (optional)
  • Tongue (If you do not have scissors)

Yes, all you really need are your hands, a square piece of paper, and your tongue.

Step 3: Left corner to center

Now fold the bottom left corner so that it goes over the center fold. Make sure that the edge of the paper goes from the right bottom corner to the center crease. Pinch where the former bottom right corner meets the center line.

Step 4: Make two more sides of the triangle.

Make a fold that goes from where the pinch intersects the center to the bottom right hand corner, repeat on left side. These will become the two other sides of the triangle.

Step 5: Crease, Lick, Rip, Repeat

Now, sharply crease the right side of the triangle both ways. Then lick the crease and rip (or use scissors)

Step 6: The Triangle is finished

Below is the triangle, so now what do you do with it, Look to see in my next instructable.
icyflame3 years ago
In my math proofs class, we had to write up a proof for this and then find the folding pattern to make the largest equilateral triangle and then prove that too haha. Very cool :)
greenjedi5 years ago
i thought arches were the strongest shape
n8man (author)  greenjedi5 years ago
Nope, triangles are, why do you think that bridges have triangle shapes.
Because they're easier to build than arches.
surely a single point would be stronger than a triangle
REA5 years ago
i thought you were making a penrose triangle. =( lol
lieuwe6 years ago
wow, sort of useful, i guess
rimar20006 years ago