some ideas on how to maximize report length.

Selecting the Correct Font
Font choice plays a big role in the length of the report. From my experience, Courier New is your best choice. Courier New is a wide, fixed width font, which lengthens your writing significantly while still maintaining the professional aspect of the report. Comic Sans MS is also about as large as Courier New, but it looks goofy and some teachers may not even accept it. You may want to experiment with font size, although this is definetly an overused method of increasing report length.

MS Word has a default margin size of 1.25". Experiment with this in order to gain a few extra lines. You probably don't want to go much over 1.5" or it will be fairly obvious that you are attempting to increase length.

If the teacher requests double spacing, try going for 2.5 spacing. Most teachers won't notice the difference, but you'll definetly gain a few lines.

Make a big first page header, but try to make it look professional. Do not double space between paragraphs.

Writing Style
Avoid using pronouns wherever possible, but not to the extent of idiotic writing. Also, avoid using abbreviations if possible. Attempt to write verbosely.

Page Numbers If you use automatic page numbering in your word processor, you can have a larger bottom margin and have a more professionally formatted report.

Maintaining Legitimacy
The most important thing to remember when applying these techniques is that any attempt to make your report longer should look legitimate.