A letter to your teacher requesting to extend time of assignment submission
100 words

Good morning/afternoon/evening (insert prefix) (teachers last name), I would appreciate if you could extend the time for the assignment submission for (a couple days, a week, etc). This way I'd be able to put in more effort to complete it and it will be completed to the best of my abilities. Thank you in advance!

Sincerely, (your name).

*If you had a family emergency be sure to add that so they would understand why you need an extension