Y you shall achieve in the midst of its square, as far as its lower half
is concerned, after the instructions before given for I; but its upper
part you shall divide so that its hither limb shall contain two-thirds,
and its farther one-third of the broad standard; and let them slope to
either side so that produced they may touch the two angles a. and b.;
and the greater circles, by which you are to round out their obtuse or
greater angles, make of a diameter as great as a containing side of the
square enclosed between the standard and the sides of the great square,
as in T was shown; but the diameters of the circles which you apply to
the lesser angles, make double the width of the broad standard, as
below.
[Illustration: Y]