Answer:
Volume = 4H^3, and
Length = 10.86 cm
Explanation:
The volume of a box is given by:
Volume = W*L*H,
where W, L, and H are the Width, Length, and Height of the box.
We are told that both the length, L, and the width, W are twice as long as the height:
L = 2H, and
W = 2H
Take the first equation and substitute these two expression for L and w:
Volume = W*L*H
Volume = (2H)*(2H)*H
Volume = 4H^3
We know the volume, so we can say:
640 cm^3 = 4H^3
4H^3 = 640 cm^3
H^3 = 160
H = 5.43 cm
L = 2H
L = 10.86 cm