What is a good way to fold a thick paper in the 3 equal sections?

Answer 1

take the longest side and divide the measurement by 3. get a ruler and and draw lines where you got your answer.

for example:
paper is 9 inches long.
it is divisible by 3.
every 3 inches I fold the paper.

that should work

Answer 2

With a pencil, eyeball the thirds and mark them with the pencil. Then measure the thirds to see which is shorter. Use a spare scrap of paper if you have no ruler. Change the pencil marks until each measures the same as the others.

OR

Use the ruler and measure the entire length. Divide this length by 3, and measure off that amount.

OR

try folding it to about one third of the paper, and see if the other fold will equal that one. tricky, but can be done.

Answer 3

I would suggest taking the ends of the paper in your hands and folding them in in equal amounts. Fold one side over the other until it looks about right. Then, crease the paper and you're done!

If this needs to be more exact, you can always take out a ruler and measure the sections.