[tex]\it \mathcal{P}=448 \Rightarrow 4\ell=448\\ \\ \ell'=5\cdot\ell\\ \\ \mathcal{P}'=4\cdot\ell'=4\cdot5\cdot\ell=5\cdot4\ell=5\cdot\mathcal{P}=5\cdot448 = 2240\ m[/tex]
2240-448= 1792m (cu cât s-a mărit perimetrul)
Sau:
[tex]\it Fie\ \mathcal{P} = 448,\ \ \mathcal{P}'=5\mathcal{P}\\ \\ \mathcal{P}'-\mathcal{P}=5\mathcal{P}-\mathcal{P}=4\mathcal{P}=4\cdot448=1792\ m[/tex]
