Many students think that if they use 18 point font, then their essay will be longer and the teacher won't notice. Make sure you use full sentences, take full advantage of spell-check or ask a friend to proofread, and try to say things as simply and clearly as possible at all times. If it takes you 10 pages to be able to do this, then as long as it is clear and well-written, you should be fine. If you're terse and can say it in 2-3 pages, that's fine too. There are advantages and disadvantages to either person, so the best idea would be to use the one you feel most comfortable with.
First person is often more informal and cordial-however, it can sound less authoritative.
Third person is more formal and authoratative at times, but can get tricky in terms of pronouns. Follow whatever convention seems best to you. Above all, make your writing sound natural, never forced or awkward. Inc. All rights reserved.