Comments on: Coin covering puzzle http://puzzletweeter.com/2014/11/27/coin-covering-puzzle/ Tweet your puzzles! Mon, 27 Jun 2016 18:15:01 +0000 hourly 1 https://wordpress.org/?v=4.4.2 By: Lizard http://puzzletweeter.com/2014/11/27/coin-covering-puzzle/#comment-6823 Tue, 02 Dec 2014 20:47:05 +0000 http://puzzletweeter.com/?p=1918#comment-6823 In the original arrangement, every point on the table is within 2R of a coin center (otherwise you could place a new coin there).

Shrink this arrangement of coin centers by 1/2. Now every point (of the shrunken rectangle) is within R of a coin center, i.e. every point is covered. The original table can be tiled with 4 copies of this.

]]>
By: Sid Hollander http://puzzletweeter.com/2014/11/27/coin-covering-puzzle/#comment-6808 Fri, 28 Nov 2014 22:31:46 +0000 http://puzzletweeter.com/?p=1918#comment-6808 Appears problem can be rephrased as the following without distortion.
4 coins of radius R are placed with their centers on the corners of a square table having a diagonal of 4R. (This is my 'best' worst case'. ie. it ALMOST meets requirements because a coin will fit in the central hole. Now to prove that this square of sides of 2R * root 2 can be painted with 16 coins. As it sits now the square has an area of 8r^2 square units. Utilizing only area of the largesr squares contains a coin it is clear the area may be tiled with the coins available.

]]>