Odpowiedź:
3.
[tex](40 - 4 - 4) \div 4 = 32 \div 4 = 8[/tex]
[tex]8 \times 9 = 72[/tex]
Pole tego równoległoboku wynosi
[tex]72cm^{2} [/tex]
4.
[tex]3 \times 6 = 18[/tex] 18cm^{2}
[tex] \frac{4 \times 2 + 10 \times 2}{2} = \frac{20 \times 8}{2} = 10 \times 8 = 80 \: \: \: 80cm^{2} [/tex]
[tex] \frac{(5 + 5 + 1) \times 4}{2} = \frac{11 \times 4}{2} = \frac{44}{2} = 22 \: \: \: \: \: \: \: \: \: 22cm^{2} [/tex]
