How to write requesting letter?

You did not specify the type of letter. A letter of request can be written in a formal as well as an informal format.

Here is a sample for your reference:

Q1. Write a letter to the principal of a school, asking for permission for a library period.

[[S]]

Asha Pandit 

Grade-VI, 

Class Representative

Modern Indian School, 

Rampur, New Delhi 

08 August, 2011

To, 

Mr. Ram Chand 

The Principal, 

Modern Indian School, 

Rampur, New Delhi 

Dear Sir, 

Subject: Permission for Library Period. 

I am a student of Grade-VI, Section-B. I am the class representative and thus, am writing this letter on behalf of the entire class. 

This is to bring to your kind notice that we need to avail the facility of the library to the utmost. It is very necessary for us to read newspapers, journals, reference books and fiction/non-fiction books for the overall development of our personality. 

Thus, we would be highly obliged if you could grant us the permission to visit the library everyday for an entire period. 

We would be grateful for the same. The request has been extended by everyone undersigned. Thanking you in anticipation. 

Yours faithfully, 

Asha Pandit.