Question

Ma puteti ajuta? Va rogg​

Answer 1

Răspuns:

DE || BC => $\frac{AD}{AB} = \frac{AE}{AC}$ => $\frac{2}{3} =\frac{AE}{21}$ => AE = 7 x 2 => AE = 14 cm ( din Thales )

AE + EC = AC => EC = AC - AE = 21 - 14 = 7 cm

raspuns : A) 7 CM

( am zis AD/AB = 2/3 pt ca ni se spune ca AD = 2 DB iar AD + DB = AB

=> AB = 3DB dar AB = DB + AD => AD = 3DB - DB  <=> AD = 2DB

iar AD/AB = 2DB/3DB = 2/3 )