Question

a) va rog repede e urgent rău rău va rog​

Answer 1

ΔABC ~ ΔDEF ⇒

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

$= \dfrac{\mathcal{P}_{\Delta ABC}}{\mathcal{P}_{\Delta DEF}} = \dfrac{7 + 8 + 10}{75} = \dfrac{25}{75} = \dfrac{1}{3}$

=>

$\dfrac{AB}{DE} = \dfrac{7}{DE} = \dfrac{1}{3} \iff DE = 7 \cdot 3 = 21 \ cm$

$\dfrac{BC}{EF} = \dfrac{8}{EF} = \dfrac{1}{3} \implies EF = 8 \cdot 3 = 24 \ cm$

$\dfrac{CA}{FD} = \dfrac{10}{FD} = \dfrac{1}{3} \implies EF = 10 \cdot 3 = 30 \ cm$