Answer:
7.8 cm
Explanation:
Let's find the volume of the water bottle first. The radius is 5.5/2 = 2.75 cm
V = πr²h = 3.14 * 2.75² * 20 = 474.925 cm³
If we call the minimum side length of the cube as x we can write:
x³ = 474.925 because the volume of the cube is x * x * x = x³
x ≈ 8 cm