How to Make a Paper Plane

The materials are cheap and only require paper, a pair of scissors, a ruler, and some-double sided sticky tape to complete.

1. First, make the centre vertical line by folding the paper in half vertically.
2. Then, fold both comers on the top into the centre line.
3. Next, fold the tip toward you and leave about 2 cm at the bottom part;
4. Fold each of the comers into the centre line again.
5. Fold the remaining tip over at the centre line to lock the two flaps.
6. fold the paper in half again, following the vertical line you have made in the first step.
7. Then, make the wings by folding down each side. Leave about 2.5 cm at the bottom part.
8. Fold down the tip of each wing by 1.25 cm tall.
9. Next, make two small slits by cutting the back part of both wings. Fold up both tabs.
10. Put double-sided sticky tape on the body and stick it together. You have your plane now.

How do we lock the two flaps in place?