3. a) Aria pătrat=
[tex] {l}^{2} = {7}^{2} = > 7 \times 7 = 49 {m}^{2} [/tex]
b) Aria dreptunghi=
[tex]l \times l(mare) = 6 \times 0.2 = 1.2 {cm}^{2} [/tex]
c)
[tex] {l}^{2} = 25 = > 25 \div 2 = 5[/tex]
d)
[tex]l = 0.15 \: l(mare) = 0.15 \times 4 = > 0.6 \\ l \times l(mare) = 0.15 \times 0.6 = 0.9 {dm}^{2} [/tex]