Problem 2. The figure in the drawing is composed of 4 congruent rectangles, where one side is twice as long as the other. Calculate the perimeter of this figure, if its area is $72 \mathrm{~cm}^{2}$.
Solution. If the area of the figure is $72 \mathrm{~cm}^{2}$,

![](https://cdn.mathpix.com/cropped/2024_06_05_06e08f885cfce663e921g-06.jpg?height=231&width=236&top_left_y=324&top_left_x=1206)
then the area of each rectangle is $18 \mathrm{~cm}^{2}$. Since one side is twice as long as the other, we have $2 a \cdot a=18$, i.e., $a=3 \mathrm{~cm}$. Therefore, the sides of the rectangle are $3 \mathrm{~cm}$ and $6 \mathrm{~cm}$. Finally, the perimeter of the given figure is

$$
8 a+4 \cdot 2 a=16 a=48 \mathrm{~cm}
$$