[tex]P _{dreptunghi} = 160 m \\ L=3l \\ \\ P _{dreptunghi} =2L+2l \\ 160 m=2*3l+2l \\ 160m=6l+2l \\ 160m=8l =\ \textgreater \ l= \frac{160}{8} \\ l=20 m \\ L=3l =\ \textgreater \ L=3*20m=\ \textgreater \ L=60m \\ \\ l _{patrat} = L _{dreptunghi} =60m \\ P _{patrat} =4*l \\ P _{patrat}=4*60 \\ P _{patrat} = 240m[/tex]