**The quadrilaterals that have perpendicular diagonals are "square," "rhombus" and "kite."** A quadrilateral is a closed two-dimensional figure containing four sides with all of its interior angles having a total of 360 degrees.

In geometry, the term "diagonal" refers to a segment connecting two vertices that does not form a polygon's side. A quadrilateral is said to contain perpendicular diagonals if four 90-degree angles are formed at the intersection of these diagonal lines. Diagonals that divide each other into two equal halves are called "perpendicular bisecting diagonals" or "perpendicular bisectors." Some quadrilaterals that do not contain perpendicular diagonals are rectangles, parallelograms and trapezoids.