Răspuns:
PΔABD=18cm
Explicație pas cu pas:
AC-bisectoarea ∡BAD⇒m(∡BAC)=m(∡DAC)
m(∡BAD)=m(∡DAC)+m(∡BAC)=2×m(∡BAC)=2×30°=60°
AB=BC=CD=AD=[tex]\frac{PerimetruABDC}{4}[/tex]=[tex]\frac{24}{4}[/tex]=6cm
AD=AB⇒ΔABD-isoscel
m(∡BAD)=60° }⇒ΔABD-echilateral
PerimetrulΔABD=3×AB=3×6=18 cm