Question

Triunghiurile isoscele ABC, ABD au baza [AB] şi Ce Int (ABD). Dacă
m(ADB) = m(<BAC) = 42° atunci m(<ACD) este ....​

Answer 1

$\it \Delta ABC-isoscel, cu \ baza\ [AB] \Rightarrow m(\widehat{ABC})=m(\widehat{BAC})=42^o \Rightarrow \\ \\ \Rightarrow m(\widehat{BCA})=189^o-2\cdot42^o=96^o\\ \\ \\ \Delta DAC \equiv \Delta DBC\ (caz\ LLL) \Rightarrow m(\widehat{ACD})=m(\widehat{BCD})=\dfrac{360^o-96^o}{2}=132^o$