Height: h=8/a2
Materials used in this way are:
The range of a2+4XaXh=a2+32/a a is (a >;; 0)
That is, to find the minimum value of this function (S=a2+32/a), you can take the derivative first.
2a-32/a2=0
a3= 16
Then you can know the length, height and width.