Question 333419
We know that the surface area of the entire board is 9600 cm^2.

If we want to divide that up into 45 equal squares, you would want to see what the area of each square has to be:

{{{9600 / 45 = 640 / 3}}}

So the area of each square has to be 640 / 3.

We know the area for any rectangle is {{{b * h = A}}}, however, for a square we know that b = h, so we get {{{b^2 = A}}}

Finally, combining it with our last example, we get:

{{{b^2 = A = 640/3}}} => {{{b^2 = 640/3}}} => {{{b = +- 8 * sqrt(10/3)}}} 

Since we are working with distance, we would take the positive answer.

{{{b = 8 * sqrt(10/3) }}}