kost av kan=metal for the skin, so kost=konstant*aea av kan . . . so yu need tu minimize area/volume . . . tin kan=cylinder . . . .....volume=(base area)*hite & base area=pi*radius*radius . . . area=sides +2 ends . . . side=hite*2*pi*radius . . . 1 end area=pi*radius+radus . . . area=2*pi*radius*hite + pi*radius*radius . . . area=pi*radius*(2*hite +radius) . . . area / volume=pi*radius*(2*hite+radius) / pi*radius*radius . . . =(2*hite+radius)/radius . . . also hav rule...volume=konstant=base*hite . . . if yu inkreez hite, gotta kut area & also the opposut . . . in other werds, d(hite)=-d(base area ) d=0 at hite=radius/2