Now, a square figure has these lines, four in number, all equal?

Certainly.

And these, drawn through the middle,

Yes.

And a figure of this sort may be larger or smaller?

To be sure.

Now if this side were two feet and that also two, how many feet would the whole be? Or let me put it thus: if one way it were two feet, and only one foot the other, of course the space would be two feet taken once ?

Yes.