Răspuns :
[tex]l_\square=30 \ cm \\ P_\square=4l_\square =4 \cdot 30 \ cm=\boxed{120 \ cm}; \\ A_\square=l_\square ^2=(30 \ cm)^2=\boxed{900 \ cm^2}[/tex]
[tex]l_\square=30 \ cm \\ P_\square=4l_\square =4 \cdot 30 \ cm=\boxed{120 \ cm}; \\ A_\square=l_\square ^2=(30 \ cm)^2=\boxed{900 \ cm^2}[/tex]