Theory:

Square is one of the most basic shapes. A square is a quadrilateral with four equal sides & four equal angles.
 
sqare.png
 
Basic properties of a square are:
  • Equality
  • Bisection
  • Perpendicularity
Equality:
  • Opposite sides of a square are parallel and equal in length.
  • All four angles of a square are equal. (Each is \(360°/4\) \(=\) \( 90°\), so every angle of a square is a right angle.)
  • The diagonals of a square are equal.
  • All four sides of a square are equal.
Bisection:
  • The diagonals of a square bisect each other.
  • The diagonals of a square bisect its angles.         
Perpendicularity: 
  • All the angles of the square are equal to \(90°\).
  • Diagonals meet at \(90°\).