Make a Triangle from a Square: method 2
Some origami models start with an equilateral triangle instead of a square sheet of paper. In this case, you need to make the triangular sheets of paper before you start. This page will show you one method to achieve this. There is a another method which is slightly easier, but the resulting triangle is smaller. You can also make a triangle from a rectangular sheet of paper.
- Fold and unfold a square sheet of paper in half vertically and horizontally.
- Fold and unfold the top-left corner so it meets with the horizontal crease made in step 1 (align the red dots). Be sure the crease extends to the top-right corner.
Do the same with the bottom-right corner: fold it up so it meets with the vertical crease line (align the black dots). This crease should also extend to the top-right corner. Unfold.
- Take note the location where the crease lines made in step 2 meet the raw edge of the paper (black dots). Fold the paper so a new crease is made which connects the two dots.
- Cut along the creases to get an equilateral triangle. This method produces the largest equilateral triangle from a square sheet.