Square is a parallelogram where

all sides are equal and all angles are 90°

**
Properties of Square:
**

Since it is a parallelogram,

it will have all its properties

In parallelogram

Opposite sides are equalOpposite angles are equalDiagonals bisect each otherSum of adjacent angles is 180°

Other properties are

Diagonals are of equal length

i.e. AC = BD