oblicz dlugosc przekatnej sciany bocznej (1)

[tex] {d}^{2} = {4}^{2} + (2 \sqrt{5} {)}^{2} \\ {d}^{2} = 16 + 4 \times 5 \\ {d}^{2} = 16 + 20 \\ {d}^{2} = 36 \\ \boxed{d = 6}[/tex]