Square is two dimensional shape. Perimeter is distance around a two dimensional shape. Let's consider the length of a side of a square is variable "a". As four sides of square are always equal so we can write our formula for Perimeter as given below
Perimeter of Square = a+a+a+a
OR simply
Perimeter of Square =4a
Perimeter of Square = a+a+a+a
OR simply
Perimeter of Square =4a
How to Find Perimeter of a Square - 7th Grade Math