Use your ruler to connect one of the points marked in step 4 to the center of the longest side of the small triangle. This should result in a new even smaller triangle and a parallelogram. From the other point from step 4, draw a short perpendicular line connecting it to the nearby corner of your second triangle. This line should create a small square and small triangle.
Step 6: Your original square should now be divided into seven different shapes: 2 small triangles, 2 large triangles, 1 medium triangle, 1 square, and 1 parallelogram. If it looks right, go ahead and cut out the shapes!