Răspuns :
[tex]\it Compar\breve am\ \Delta ABD\ cu\ \Delta BMQ:\\ \\ \left.\begin{aligned}AB\equiv MB\ (laturi \ ale\ p\breve atratului\ ABMN)\ \ \ \ \\ \\ \widehat{DAB}\equiv\widehat{QBM}\ (au\ acela\c{s}i\ suplement,\ \widehat{ABC})\\ \\ AA\equiv BC\equiv BQ\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \end{aligned}\right\} \stackrel{LUL}{\Longrightarrow} \Delta ABD \equiv \Delta BMQ \Rightarrow\\ \\ \\ \Rightarrow BD\equiv MQ[/tex]