Start out with a square piece of paper, preferably thin or lightweight paper. You can use square origami paper or follow these easy steps for making a square from any rectangular piece of paper.
Turn the triangle so that the solid corner (the corner corresponding to the paper's center) is at the bottom. Divide the triangle into 3 equal sections, each with a 30 degree angle. The most accurate way to do this is to use a protractor. If you don't have a protractor, you can estimate the size of the sections as you do Steps 5 and 6.