Question

se considera triunghiul abc in care mA=35° si mB=4m(C). atunci mB este

Answer 1

Răspuns:

Explicație pas cu pas:

Suma unghiurilor intr-un triunghi este 180°

m(A) + m(B) + m(C) = 180°

m(B) + m(C) = 180° - m(A) = 180° - 35° = 145°

m(B) = 4m(C)

4m(C) + m(C) = 145°

5m(C) = 145°

m(C) = 145° : 5 = 29°

m(B) = 4*29° = 116°

Answer 2

$\it m(\hat A)+m(\hat B)+m(\hat C)=180^o \Rightarrow m(\hat B)+m(\hat C)=180^o -m(\hat A)\Rightarrow \\ \\ \Rightarrow m(\hat B)+m(\hat C)=180^o-35^o \Rightarrow m(\hat B)+m(\hat C)=145^o \ \ \ \ \ (1)\\ \\ m(\hat B)=4m(\hat C)\ \ \ \ \ (2)\\ \\ (1),\ (2) \Rightarrow 4m(\hat C)+m(\hat C)=145^o \Rightarrow 5m(\hat C)=145^o|_{:5} \Rightarrow m(\hat C)=29^o\ \ \ \ \ (3)\\ \\ (2),\ (3) \Rightarrow m(\hat B) =4\cdot29^o=116^o$