Răspuns :
construim AA' _|_ BC
in Δ ABA' AA' = AB/2 = 4cm
A ΔABC = BC·AA' /2 = 5·4/2 = 10 cm²
in Δ ABA' AA' = AB/2 = 4cm
A ΔABC = BC·AA' /2 = 5·4/2 = 10 cm²
AB=8cm,
BC=5cm,
Unghiul B=30°,
AC=?
AB=AC⇒AC=8cm
Unghiul B=30°⇒unghiul C=30°,
⇒∆ABC-isoscel.
[tex] A_{ABC} = \frac{AB*AC}{2} = \frac{8*8}{2} = \frac{64}{2} =32cm[/tex]