Drawing the Great Icosahedron
Step 2. Draw a vertical line 290 mm. long down the
centre of the page along the fold line.
Step 1. Take a sheet of A3 paper and fold it in half
Step 3. Draw  a rectangle to the dimensions shown  
around the centre line of the page
Step 4. Draw in the heavy black lines as shown.
Step 5. Draw a horizontal line to the dimensions
shown.
Step 6. Draw in the heavy black lines as shown.