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Five Points in a Square
There are 5 points in a square 1×1. Show that 2 of the points are within distance 0.75.
SOLUTION
Split the unit square into 4 small squares with side lengths 0.5. At least one of these squares will contain 2 of the points. Since the diagonals of the small squares have lengths less than 0.75, these 2 points must be within such distance.
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