[13] Outside reverse fold downward along the second crease line made in step 10.
[14] Fold the top layer of triangle XYZ to the left.
[15] Fold the top layer of triangle ABC downward.
[16] Open the top layer of triangle CAD and flatten it into a square by gripping point B between your fingers and pulling upward and to the left. Figures 16a and 16b show you how to do this.
