If the area of the quadrilateral PQRS is 15 cm2 .What will be the length of QS?

To find the length of diagonal $QS$ in the quadrilateral $PQRS$ with a given area of 15 cm², we need more specific information about the quadrilateral, such as the lengths of the sides or the angles. The area alone is not sufficient to determine the length of a diagonal without additional constraints.

Generally, the area $A$ of a quadrilateral can be calculated using various methods, such as Brahmagupta's formula for cyclic quadrilaterals or decomposing the quadrilateral into triangles if the lengths or angles are known.

If you can provide additional details about the quadrilateral, such as side lengths or angles, I would be able to help you find the length of $QS$.