4.
[tex] {a}^{2} = 100 {cm}^{2} \\ a = 10cm[/tex]
6.
[tex] {a}^{2} = 36 {cm}^{2} \\ a = 6cm[/tex]
Zatem obwód
[tex]6cm \times 4 = 24cm[/tex]
7.
[tex]64 = \frac{8 \times f}{2} | \times 2 \\ 128 = 8f | \div 8 \\ f = 16[/tex]
