MathDB

1

Part of 2009 Argentina Team Selection Test

Problems(1)

No right-angled triangle

Source: Argentina TST 2009

5/15/2009
On a 50×50 50 \times 50 board, the centers of several unit squares are colored black. Find the maximum number of centers that can be colored black in such a way that no three black points form a right-angled triangle.
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