Question

plsss ajutor.........​

Answer 1

Explicație pas cu pas:

DE || BC => ΔADE ~ ΔABC

BC = 3DE, AE = 2 cm

$\frac{DE}{BC} = \frac{AE}{AC} < = > \frac{DE}{3DE} = \frac{2}{AC} \\ \frac{1}{3} = \frac{2}{AC} = > AC = 6 \: cm$

EC = AC - AE = 6 - 2 = 4

=> EC = 4 cm