triunghiu ABC asemenea cu triunghiul DEC (unghiu A= unghiul E)
[tex] \frac{EC}{AC} = \frac{DE}{AB} = \frac{CD}{BC} \\ \frac{EC}{8} = \frac{DE}{6}= \frac{5}{10} \\ \frac{DE}{6} = \frac{5}{10} \\ DE= \frac{5*6}{10} =3 \\ \frac{EC}{8} = \frac{5}{10} \\ EC= \frac{8*5}{10} =4
\\ P=CD+DE+CE=3+4+5=12[/tex]