mas< AOB = 80grade ; mas< BOC = 40 grade ⇒ mas< AOC = 120 grade
ducem OM_|_AC (coarda AC)
in ΔAOM (dreptunghic) mas< AOM = 60 grade (1/2din 120) ⇒ mas<OAM = 30 grd
⇒⇒ OM = OA/2 = R/2 = 12 cm
AM² = AO² - OM² = 576 - 144 = 432 AM = 12√3 cm
AC = 2AM = 24√3 cm