BD=AB-AD=42-5,2=36,8 (mm)
AE=AC-CE=63-1,5=61,5 (mm)
[tex] \frac{AD}{BD} [/tex]=[tex] \frac{5,2}{36,8} = \frac{52}{368} = \frac{13}{92} [/tex]
[tex] \frac{AE}{CE} = \frac{61,5}{1,5} = \frac{615}{15} = 41[/tex]
Cum [tex] \frac{13}{92} \neq 41 => \frac{AD}{BD} \neq \frac{AE}{CE} [/tex] => DE nu e paralel cu BC.