Question

a) va rog frumos frumos​

Answer 1

ΔABC ~ ΔDEF ⇒

$\dfrac{AB}{DE} = \dfrac{BC}{EF} = \dfrac{CA}{FD} = \dfrac{2}{5}$

a)

$\dfrac{AB}{DE} = \dfrac{2}{5} \iff \dfrac{10}{DE} = \dfrac{2}{5} \\ \implies DE = \dfrac{5 \cdot 10}{2} = 25 \ cm$

$\dfrac{BC}{EF} = \dfrac{2}{5} \iff \dfrac{15}{EF} = \dfrac{2}{5} \\ \implies EF = \dfrac{5 \cdot 15}{2} = 37.5 \ cm$

$\dfrac{CA}{FD} = \dfrac{2}{5} \iff \dfrac{20}{FD} = \dfrac{2}{5} \\ \implies EF = \dfrac{5 \cdot 20}{2} = 50 \ cm$

b)

$\dfrac{AB}{DE} = \dfrac{2}{5} \iff \dfrac{AB}{10} = \dfrac{2}{5} \\ \implies AB = \dfrac{2 \cdot 10}{5} = 4 \ cm$

$\dfrac{BC}{EF} = \dfrac{2}{5} \iff \dfrac{BC}{14} = \dfrac{2}{5} \\ \implies BC = \dfrac{14 \cdot 2}{5} = 5.6 \ cm$

$\dfrac{CA}{FD} = \dfrac{2}{5} \iff \dfrac{CA}{22} = \dfrac{2}{5} \\ \implies CA = \dfrac{22 \cdot 2}{5} = 8.8 \ cm$