Jan Tschichold's Layout

We set up a symmetrical grid based on Jan Tschichold's layout; we opened a new sheet of paper in illustrator with the size A4  in the portrait format. after I did this I placed in diagonal lines across the both papers and created the shape above. after I did this I opened the ruler set up and put in the y axis as shown above. after tht i placed in two boxers to show how textbook layouts are created.