Question

Va rog ajutati-ma..................

Answer 1

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Answer 2

a)

$\it EF || BC \Rightarrow \widehat{EBC} \equiv \widehat{FEB} \ (alterne\ \ interne) \ \ \ \ (1) \\ \\ BE -bisectoare \ \Rightarrow \widehat{EBC} \equiv \widehat{EBF} \ \ \ \ \ (2) \\ \\ (1),\ (2) \Rightarrow \widehat{FEB} \equiv \widehat{EBF} \Rightarrow \Delta FBE - isoscel \Rightarrow BF = EF = 18\ cm$

b)

$\it EF || BC \Rightarrow \widehat{ACB} \equiv \widehat{AEF} \ (corespondente) \Rightarrow m(\widehat{ACB}) = m(\widehat{AEF}) =47^o \\ \\ \\ m(\hat A) = 180^o- m(\hat B) -m(\hat C) =180^o -86^o-47^o = 47^o$