Write a letter to your class teacher, requesting for leave for ten days

Sir

Sub: Request for leave

As I am feeling sick and the doctor has diagnosed viral fever, I will not be able to attend school for about ten days. Kindly grant me leave from attending class for ten days, i.e. upto the fourteenth of this month. I hope I will be able to attend school on 14th.

Thanking you

Yours faithfully