Regardless of the size of the square, half the diagonal is (√2)/2 times the side of the square.
The ratio is (√2)/2.
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Consider a square of side length 1. The Pythagorean theorem tells you the diagonal measure (d) is ...
... d² = 1² +1² = 2
... d = √2
The distance from the center of the square to one of its corners (on the circumscribing circle) is then d/2 = (√2)/2. This is the radius of the circle in which our unit square is inscribed.
Since we're only interested in the ratio of the radius to the side length, using a side length of 1 gets us to that ratio directly.
It is almost impossible to end inflation and high unemployment at the same time because as more people get money and unemployment goes down there will be high demands in good which will result in inflation.
