Odpowiedź:
[tex]6^{2} + 8^{2} = a^{2}[/tex]
[tex]36 + 64 = a^{2}[/tex]
[tex]a^{2} = 100[/tex]
a = 10 ∈ D ∨ a = -10 ∉ D
a = 10
