Sum of the four interior angles of a quadrilateral is four times the measure of a right angle.

One diagonal of a quadrilateral divides it into four triangles.

There are four pairs of adjacent angles in a quadrilateral.

There are four pairs of opposite angles in a quadrilateral.

It is not possible that each angle of a quadrilateral be $90°$.

Three angles of a quadrilateral are of $80°$ each. Determine the fourth angle.

If in a quadrilateral, only one pair of opposite sides is parallel, then such a quadrilateral is called _____.

Each angle of a rectangle is of _____ degrees.

A parallelogram in which each angle is of $90°$ and all sides are of equal lengths is called _____.