Puzzle 2

Connect all nine dots, without lifting pencil from the paper, using 4 straight lines

History of the Puzzle

The nine dot problem is a classic lateral thinking exercise that gained widespread popularity in the 1970's and 80's. Participants are presented with a set of dots arranged in a 3x3 grid and challenged to connect all nine dots, without lifting their pencil from the paper, using the fewest possible number of straight lines. 

Copy the simple diagram above onto a piece of paper and give the puzzle a try.

The solution requires one to "think outside the box" and, some contend, that the nine dot problem served as the inspiration for this popular phrase.

Sources and Solution

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