Hey there!
First, divide 175 by 7. You get 25. Since a sqaure has all equal sides, sqaure root 25. You get 5. The length of a side of the base is 5 inches. To check our work, multiply length times width times height. 5 x 5 x 7 =175. This is the volume. This confirms that the answer is 5 inches.
I hope this helps!