[tex]1.[/tex][tex]ABCD ~trapez~oarecare.MN~ linia~mijlocie~conform~formulei.\\
\boxed{l= \frac{a+b}{2}} ~~~unde~\boxed{l->ilinea~mijlocie}~~~si ~~~\boxed{a->baza~mica}~~~si \\\\
\boxed{b->baza~mare}.\\\\
\boxed{\boxed{a+b=15*2=30}}[/tex]
[tex]\boxed{\boxed{\boxed{\boxed{La ~2~nu ~stiu~scuzeee!}}}}[/tex]