Question

Daca triunghiul ABC ~triunghiulDEF, AB=10cm,AC=14cm si DE=5 cm, atunci DF are lungimea egala cu: A.7cm; B.3√3 cm; C.8 cm; D.2√3 cm.

Answer 1

AB/AC = DE/DF

10/14 = 5/DF

DF = 14·5/10 = 70/10 = 7 cm 

Raspuns : a) 7 cm

Answer 2

$\it \Delta ABC \sim \Delta DE F \Rightarrow \dfrac{AB}{DE} = \dfrac{AC}{DF} \Rightarrow \dfrac{10}{5} = \dfrac{14}{DF} \Rightarrow 2=\dfrac{14}{DF} \Rightarrow DF=7cm$