 From now on, crease the entire length of every fold.
Valley fold in half,
so that the pinch made in Step 11 is in the near layer.
 Valley fold
the folded lower corner to exactly meet the pinch made in Step 11.
Note: If folded exactly, the pinch made in Step 11 is exactly 35 percent of the way
in from the open edge of the paper. (35 percent is a little more than onethird.)
This means that all 10 central angles of the pentagon will be almost exactly 36 degrees,
causing the pentagon to be almost perfectly regular.
Here is the math:
1  2 * sin(36 deg.) / (1+ cos(36 deg.) ) = 0.35016
On a 6 inch square, the error is less than onequarter of the thickness of the paper.
 Valley fold
the new flap in half.
 Valley fold,
so that the main diagonal lines up with the new edge.
 Like so. Turn over from sidetoside.
