If you can tell me what the missing number is.

6

Step-by-step explanation:

So, to start answering this, lets recall the formula for a rectangles volume:

This formula is :

V=h*w*l

Lets plug in what we know, and solve for the missing variable.

We know that height(h) is 7.

We know that width(w) is 9.

We know that volume(V) is 378.

We are missing length(l)

So:

378=7*9*l

To find length(l), we must iscolate it.

To do this, we must get rid of the 7 and 9.

So lets start by dividing 378 by 9:

378/9=7*9/9*l

=

42=7*l

Now lets do the same thing with the 7 to iscolate l:

42/7=7/7*l

=

6=l

So our missing length(l) is 6.

l = 6

Hope this helps!

the square root of what number? if you add that, then someone will probably answer the question.