[tex]a = (a - 1)[/tex]
[tex]b = (a - 1) + 2 = a + 1[/tex]
Zatem obwód
[tex]2((a - 1) + a + 1) = 2 \times 2a = 4a[/tex]
[tex] \boxed{ \boxed{Odp.B}}[/tex]
