There is a 45,45,90 triangle and a 30,60,90 triangle within triangle ABC.
So you can just use the relationships between sides in these special triangles to find the desired lengths.
AB=3√2
z=3
b=3 (It is isosceles so we know that b=z)
With b=3, we know that...
x=3·2=6
y=3√3
answers: z=3,b=3,x=6,y=3√3