[Illustration: FIG. 1., FIG 2.]
First fold the cross along the dotted line A B in Fig. 1. You then have
it in the form shown in Fig. 2. Next fold it along the dotted line C D
(where D is, of course, the centre of the cross), and you get the form
shown in Fig. 3. Now take your scissors and cut from G to F, and the
four pieces, all of the same size and shape, will fit together and form
a square, as shown in Fig. 4.
[Illustration: FIG. 3., FIG. 4.]