calculul elementelor in poligoane regulate in functie de raza cercului circumscris
l₃=12√6 cm
l₃=R√3 ⇒ R√3=12√6 cm ⇒ R=12√2 cm
a₃=R/2=12√2/2=6√2 cm
a₆=a₃=6√2
6√2=R√3/2
R=6√2×2/√3=12√2/√3=12√6/3=4√6 cm
A₆=3R²√3/2=3×(4√6)²×√3/2=3×96×√3/2=144√3 cm² raspuns corect d)