a) Pole
[tex]6 \times 3 = 18[/tex]
Obwód
[tex]2(5 + 6) = 10 + 12 = 22[/tex]
b) Pole
[tex] \frac{(5 + 11) \times 4}{2} = \frac{16 \times 4}{2} = 16 \times 2 = 32[/tex]
[tex]5 + 11 + 2 \times 5 = 16 + 10 = 26[/tex]