All the angles of a quadrilateral are equal. What special name is given to this quadrilateral?

$(1)$ If no three points out of four coplanar points are collinear,then a $\ldots \ldots \ldots$ figure formed by joining these four points in order is called a quadrilateral.
$(2)$ $A$ quadrilateral has $\ldots \ldots \ldots$ pairs of opposite sides.

$E$ and $F$ are points on diagonal $AC$ of a parallelogram $ABCD$ such that $AE = CF$. Show that $BFDE$ is a parallelogram.

Prove that in a parallelogram,the bisectors of any two consecutive angles intersect at right angles.

Perimeter of rectangle $PQRS$ is $40\, cm$. If $PQ : QR = 3 : 5$,then $RS = \ldots \ldots \ldots \, cm$.

$(1)$ $A$ quadrilateral in which only one pair of opposite sides are parallel is a $\ldots \ldots \ldots$.
$(2)$ The diagonals of a rectangle are $\ldots \ldots \ldots$.