The silver ratio is, much like the more popular golden ratio a
mathematical concept for proportions in geometrical figures.
The silver ratio of a rectangle is as follows: the ratio of the
smaller side to the longer side equals the ratio of half
the longer side to the smaller side.
| | ↑
|_ _ _ _ _ _| B
← A →
A 0.5 B
- = -----
A2 = 0.5 B2
- = -- = 0.7071...
The silver ratio is found in ISO paper sizes. For
instance, the dimensions of an A4 sheet of paper are 21.022 by 29.730
cm; a ratio of 0.7071.