[tex]P=AB+BC+AC=54\\\frac{AB}{8}= \frac{AC}{6} =>AB=\frac{8AC}{6} =\frac{4AC}{3} \\\frac{BC}{2} =\frac{AC}{3} =>BC=\frac{2AC}{3} \\P=\frac{4AC}{3}+\frac{2AC}{3}+AC=54=>6AC+3AC=54*3=162=>9AC=162\\=>AC=18\\AB=\frac{4*18}{3}=4*6=24\\BC=\frac{2*18}{3}=2*6=12[/tex]