What format of a formal letter must I use?

Your home address top right of the letter. Date of the letter below your address. The Deans address top left of the sheet. Ref: Request for extra assignments/project work for [SinfulRose] Dear Sir, Unfortunatly my daughter has been to ill to attend classes for the last six weeks and our doctors advise that they anticipate that it will be another xx weeks before a recovery is made sufficient to return to school. Copies of our doctors reports attached. It would be appreciated if her professors would kindly supply sufficient assignments/project work to allow her to continue her studies and any other assistance to help her at this critical period of her education would be much appreciated. Yours faithfully, [Hand signature] Mummy SinfulRose Please run it through a spell checker first!! I didn't get A's for English Grammer!!

The letter format described in the first comment is perfect for you Mother to follow. What I would advise is also have the doctor hand you a letter too to attach to your Mothers before handing it in to the dean of the school. It may be a requirement or may not but you are covering all the bases clarifying why you were absent and that you were truly sick. The doctor can't reveal specifics but can state that you were under his care and to make a notation that you fell sick and was out of school from this date and are now able to return to school as of this date. The two letter together should allow you to return and get an extension on the classes, test or labs that you missed out on. Feel better!

Well still in here people are not following the left side rule i mean where everthing is inleft including the signature. Suggest you to first write your adress at top ( which is leave blank didn't write for schools even now in my coll i didn't) Then "To the dean or principal with the school name then respected then for the sub or so called refernce for thereason. Then the contents which must not have more than two paragraphs. At end post you signsture.