Write a leave letter to your teacher.
To,
The Teacher

Sir/Madam,
           This is to inform you that I will be going out of station for 3 days from <date> to <date>, to attend my sister's wedding celebrations.
           I request you to kindly consider this and  grant me leave.

Yours faithfully,
XYZ
Instruction: Write a leave letter to your teacher.
Context: 
Response: To,
The Teacher

Sir/Madam,
           This is to inform you that I will be going out of station for 3 days from <date> to <date>, to attend my sister's wedding celebrations.
           I request you to kindly consider this and  grant me leave.

Yours faithfully,
XYZ