In ΔWYZ: 

hyp\(^2\) = adj\(^2\) + opp\(^2\)

hyp\(^2\) =3\(^2\) + 4\(^2\) → 9 + 16

hyp\(^2\) = 25

hyp = 5

In ΔWXY:

hyp\(^2\) = adj\(^2\) + opp\(^2\)

hyp\(^2\) = 12\(^2\) + 5\(^2\) = 144 +25

hyp\(^2\) = 169

hyp = 13

the perimeter of WXYZ. = 3+4+12+13 → 32cm