Let's call x the edge length of that cube.
The volume V of a cube with edge length x is:
V = x³
We know that the volume of that cube is V = 8 ft³. So, in order to find the edge length x, we can replace V by 8 ft² in the above relation:
V = x³
8 ft³ = x³
Now we can rewrite 8 as 2³ since
2³ = 2 * 2 * 2 = 8
So, we find:
8 ft³ = x³
2³ ft³ = x³
Now, since 2³ and ft³ have both the same exponent, we can write:
2³ ft³ = (2 ft)³
So, we have:
(2 ft)³ = x³
And since we have the same odd exponent for both sides of the equation, the basis must be the same:
2 ft = x
x = 2 ft
Therefore, the edge length is 2 ft.