I've been presented with this problem...

" If the smallest square has dimensions 1 x 1, what is the AREA of the rectangle ABCD. This problem is not to be solved using a ruler. "

The square then looks like:

Where I drew a line out is the smallest square, 1 x 1. Sorry about the bad drawing... In total there's 9 squares within the big square so I guess you could say 10 total?

So how does one go about solving this problem? Any solutions would be great.