[tex]a) \ \ Compar\breve am\ \Delta ACB\ cu\ \Delta DCB\ :\\ \\ \\ \left.\begin{aligned} \[[A C] \equiv [CD]\ \ \ \ \\ \\ \widehat{ACB} \equiv \widehat{DCB}\ \ \ \ \\ \\ \[[CB]- latur\breve a\ comun\breve a\end{aligned}\right\}\ \stackrel{LUL}{\Longrightarrow}\ \Delta ACB\equiv\Delta DCB \Rightarrow \[[AB]\equiv[DB][/tex]
b)
[tex]\it \[[AC]\equiv[CD] \Rightarrow \Delta ACD\ -\ isoscel\ \ \ \ (1)\\ \\ \\ \widehat{ACB}\equiv\widehat{DCB} \Rightarrow\[[CB\ -\ bisectoare\ pentru\ \widehat{ACD}\ \ \ \ \ (2)\\ \\ \\ (1),\ (2) \Rightarrow CB-mediatoarea\ segmentului\ \[[AD] \Rightarrow CB\perp AD[/tex]
