By definition, when two figures are similar the ratios of the lengths of their corresponding sides are equal and their corresponding angles are congruent.
Knowing that the rectangles shown in the exercise are similar, you can set up the following proportion:
![(24)/(16)=(x)/(6)](https://img.qammunity.org/2023/formulas/mathematics/college/rrbzzuhxr6e3pc1m517lkl78l7sn3bckxz.png)
Then, you have to solve for the variable "x" in order to find its value. You get that this is:
![\begin{gathered} (6)((24)/(16))=x \\ \\ (144)/(16)=x \\ \\ x=9 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/2th6ffc0bp27e605teq6bhb0356e0lqqxv.png)
The answer is:
![x=9](https://img.qammunity.org/2023/formulas/mathematics/high-school/cmoob0b43q6h3m27uzhcp4tu0db7ka7bi8.png)