Isospin Symmetry

Question

Hi everyone,

I am studying isospin symmetry now. I have the decay $K_1^+(1270) \rightarrow K^*(892) \pi \rightarrow K \pi \pi$. The intermediate state could either be $K^{*+}(892) \pi^0$ or $K^{*0}(892) \pi^+$. The final states are $K^+ \pi^0 \pi^0$, $K^+ \pi^+ \pi^-$ and $K^0 \pi^+ \pi^0$. I have some troubles with calculating the branching ratios of the final states using Clebsch-Gordon coefficients. Do you have any ideas?

Thanks for everything!