[tex]\it bc=120\ \ \ \ \ (1)\\ \\ tgC=\dfrac{c}{b}=\dfrac{6}{5}=1,2 \Rightarrow c=1,2b\ \ \ \ \ (2)\\ \\ (1),\ (2) \Rightarrow b\cdot1,2\cdot b=120 \Rightarrow 1,2b^2=120|_{\cdot10} \Rightarrow 12b^2=1200|_{:12} \Rightarrow \\ \\ \Rightarrow b^2=100=10^2 \Rightarrow b=10\ \ \ \ \ (3)\\ \\ (2),\ (3) \Rightarrow c=1,2\cdot10 \Rightarrow c=12[/tex]
[tex]\it \Delta ABC-dr,\ \widehat{A}=90^o,\ \stackrel{T.P.}{\Longrightarrow}\ a^2=b^2+c^2=10^2+12^2=100+144=244\\ \\ a=\sqrt{244}=\sqrt{4\cdot61}=2\sqrt{61}\\ \\ \mathcal{P}=a+b+c=2\sqrt{61}+10+12=2\sqrt{}61+22=22+2\sqrt{61}[/tex]
