Here is how I approached it
\(xyz=720\\ xy+xz+yz=333\\ \sqrt[3]{333}\approx 8.9\)
this means that at least one of the dimensions is 8 or less, and at least one is 9 or more
Factor 720 and you get
\(720=2^4*3^2*5\)
the factors 8 and smaller are 1,2,3,4,5,6,8
Try x=8
If x=8 then yz=720/8 = 90
8y+8z+90=333 so 8y+8z = 333-90 = 243
But 243 is not divisable by 8 so 8 is not one ofthe dimensions.
Try x=6 I ran into the same problem
Try x=5 same problem
Try x=4 same problem
Try x=3
If x=3 then yz= 720/3 = 240
3y+3z+240=333
3y+3z=93 so y+z=31
31=15+16, that sounds promising
If the sides, x,y and z are 3, 15, and 16 then
(3*15)+(3*16)+(15*16) = 45+48+240 = 333 Bingo
the sides are 3,15 and 16