[tex]\it ABC-dr,\ \widehat{B}=90^o, BD\perp AC, D\in AC\ \stackrel{T.catetei}{\Longrightarrow}\ BC^2=CD\cdot CA \Rightarrow \\ \\ \Rightarrow 16^2=12,8\cdot CA \Rightarrow 256=12,8\cdot CA|_{\cdot10} \Rightarrow 2560=128\cdot CA|_{:128} \Rightarrow \\ \\ \Rightarrow CA=20\ cm[/tex]
[tex]\it ABC-dr,\ \widehat{B}=90^o,\ \stackrel{T.P.}{\Longrightarrow}\ AB^2=CA^2-BC^2=20^2-16^2=400-256=\\ \\ =144=12^2 \Rightarrow AB=12\ cm\\ \\ \mathcal{P}_{ABC}=AB+BC+CA=12+16+20=48\ cm[/tex]
