If a straight-line is cut in half,
and any straight-line added to it straight-on, then the sum of the square on the whole (straight-line)
with the (straight-line) having been added,
and the (square) on the (straight-line) having been added,
is double the (sum of the square) on half.
(the straight-line),
and the square described on the sum of half (the straight-line) and (straight-line) having been added, as on one (complete straight-line).