thevenin resistance Definition and 1 Threads

So , max power is dissipated when the load resistance and thevenin resistance becomes equal such that $$P\leq \frac{V_{\text{th}}^2}{4R_{\text{th}}}$$ Then i applied the 'star delta' transformation by converting the 'delta' ABC to 'star' ABC . From there , by loop current method , i got...