**Finding the Length of the Diagonal in a Quadrilateral**

To find the length of the diagonal in a quadrilateral, we need to have additional information about the shape of the quadrilateral. In this case, we are given that the area of the quadrilateral is 60 cm². Unfortunately, without any further information or constraints, we cannot determine the length of the diagonal.

**Explanation:**

1. Quadrilateral PQRS:
Let's assume that the given quadrilateral is PQRS. Without any specific information about the shape or angles of the quadrilateral, we cannot determine the length of the diagonal. The length of the diagonal can vary depending on the specific shape of the quadrilateral.

2. Area of the Quadrilateral:
The area of the quadrilateral is given as 60 cm². The area of a quadrilateral is typically calculated using the formula:
Area = (1/2) × d₁ × d₂ × sin(angle between the diagonals)

Since we don't have the length of the diagonals or the angle between them, we cannot directly use this formula to find the length of the diagonal.

3. Additional Information:
To find the length of the diagonal, we would need additional information such as the lengths of the sides, the angles between the sides, or any other constraints that define the shape of the quadrilateral. Without this additional information, it is not possible to determine the length of the diagonal.

Therefore, without any further information or constraints, it is not possible to find the length of the diagonal in the given quadrilateral with an area of 60 cm².

Note: It is important to provide more specific information or constraints to solve a geometry problem.