What happens next?

How to make an essay appear longer than it is
Choose a slightly larger font.
If your teacher is unclear about which fonts you can use, pick one of the larger fonts like arial, courier new, bangla sangam mn, or cambria. If your teacher limits the font to times new roman, try choosing a similar, but larger font like bookman old style.
Don't pick a very large font like arial black or lucida handwriting. Your teacher will notice that you are trying to make your essay longer by choosing a larger font.