The figure shows the top left-hand corner of the complete diagram
and we see by symmetry that the perpendicular from the corner to
short side of the rectangle has length 1/2. Thus the
diagonal of the square may be divided into three sections of length
1/2, x and 1/2 respectively.
The length of this diagonal
| = |
| ________
Ö102 + 102
|
= |
| ___
Ö200
|
= 10Ö2
|
, so x = 10Ö2 -1.
