Vì \(\Delta ABC=\Delta DEF\) nên \(\widehat{A}\) = \(\widehat{D}\) = \(55^o\)
Ta có : \(\widehat{D}\) + \(\widehat{E}\) + \(\widehat{F}\) = \(180^o\)
\(\widehat{F}\) = \(180^o\) - \(\widehat{D}\) - \(\widehat{E}\)
\(\widehat{F}\) = \(180^o\)- \(55^o\) - \(75^o\)
\(\widehat{F}\) = \(50^o\)
Vì \(\Delta ABC=\Delta DEF\) nên \(\widehat{B}\) = \(\widehat{E}\) = \(75^o\)
∠A = ∠D = 55o
∠B = ∠E = 75o
∠C = ∠F = 180o - (55o + 75o) = 50o
Lời giải:
Vì ΔABC=ΔDEF nên :∠ A =∠D ; ∠B =∠E ;∠ C = ∠F
Mà ∠A =55o;∠E =75 suy ra: ∠D =55o;∠B =75
Trong ΔABC, ta có:∠ A +∠B +∠C =180o(tổng ba góc trong tam giac)
Suy ra : ∠C =180o-(∠A +∠B )=180-(55oC+75o)=50o
Vậy∠ F =50o