Dreptunghiul este echivalent cu patratul; adica [tex] A_{dreptunghi} = A_{patrat} [/tex]
[tex] A_{dreptunghi} =L*l=8*2=16 [/tex] (cm²) => [tex] A_{patrat} =16[/tex] (cm²) =>
[tex] l_{patrat} =4 (cm)[/tex]
[tex] P_{dreptunghi} = 2(L+l)=2*10=20 (cm)[/tex]
[tex] P_{patrat} =4 l_{patrat} =16 (cm)[/tex]
[tex] \frac{ P_{dreptunghi} }{ P_{patrat} } = \frac{20}{16} = \frac{5}{4} [/tex]
