The volume of any cube can be calculated as:
[tex]\text{Volume}=a^3[/tex]Where a is the width, height, and length of the cube.
So, if the volume is 125 ft cubed, the value of a can be calculated as:
[tex]\begin{gathered} 125=a^3 \\ \sqrt[3]{125}=a \\ 5=a \end{gathered}[/tex]Therefore, the width is 5, height is 5 and the length of the square chest is 5.