1. After cutting, score the bag along score lines (marked with notches in the cut out). Do this to Side 1 and Side 2.
2. Using adhesive attach the flap from Side 1 to the main piece of Side 2. Do the same with the other flap. This will give you a rectangular cylinder like what you see below.
3. To form the bottom, fold in the rectangular flap first, then the sides on top of it. You can use adhesive is desired where they overlap. The flaps coming together will form a slit (see arrow).
4. Take the last flap and slide the tab into the slit formed earlier. You can put a small amount of adhesive on this tab if desired.
5. This is what the bottom will look like when finished.
You do not need to use adhesive for the bottom unless you have something heavy in it. Hope that helps!