∫I is the intersection of the bisectors.

∴ The distances from I to AB, BC and CA are equal, all equal to ID=2.

∴S△ABC=S△ABI+S△BCI+S△ACI

∴s△abc= 1/2ab*2+ 1/2bc*2+ 1/2ac*2= 1/2*2(ab+bc+ac)

∫a b+ AC+BC = 24

∴S△ABC=24