[tex]\it \mathcal{P}_{ABC}=18+16+14=48\ cm[/tex]
[tex]\it \left.\begin{aligned}\ \it \angle A\equiv\angle D\\ \\ \it \angle B\equiv\angle E\end{aligned}\right\}\ \stackrel{(UU)}{\Longrightarrow} \Delta ABC \sim\Delta D EF \Rightarrow k=\dfrac{AB}{DE}=\dfrac{\ 18^{(6}}{12}=\dfrac{3}{2}\\ \\ \\ \dfrac{\mathcal{P}_{ABC}}{\mathcal{P}_{D EF}}=k \Rightarrow \dfrac{48}{\mathcal{P}_{D EF}}=\dfrac{3}{2} \Rightarrow \mathcal{P}_{D EF}=\dfrac{2\cdot48}{3}=2\cdot16=32\ cm[/tex]
