Explain how a square is

A quadrilateral$?$

Explain how a square is

A parallelogram$?$

Explain how a square is a rhombus$?$

Explain how a square is a rectangle$?$

Name the quadrilaterals whose diagonals:

bisect each other.

Name the quadrilaterals whose diagonals:

are perpendicular bisector of each other.

Name the quadrilaterals whose diagonals:

are equal.