Daca tri.ABC ~ tri.MNP => proportionalitatea laturilor , adica:
[tex] MN/9=NP/6=PM/8 =\;...\; = \;\frac{13,8}{9+6+8}=0,6=3/5\\
(am simplificat\;cu3\;)\\
\Rightarrow\\
MN=9\cdot\frac{3}{5}=... \;;\\
NP=6\cdot\frac{3}{5}=...\;si\\
PM=8\cdot\frac{3}{5}=...[/tex]