What special name can be given to a quadrilateral whose all angles are equal?

What special name can be given to a quadrilateral PQRS If angle P + angle S=180^(@) ?

Name the quadrilaterals whose diagonals. are equal

Name the quadrilaterals whose diagonals. are equal

Indicate the quantifier in the following statements and comment whether the statement are True or False. There exists a quadrilateral whose all sides are equal

In quadrilateral ABCD, angleA+angleD= 180^(@) . What special name can be given to this quadrilateral?