I have a diagram of 25 congruent circles in a 5 x 5 pattern, but all touching, somewhat like this:

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Just forget the spaces between the lines, imagine they are all bunched up together to form a perfect square. The question says I am to shade at least one circle so the figure has rotational symmetry of 90 degrees, but no line of symmetry. After looking at this, I fail to see how it's possible, but obviously it must be. Thank you all for your time and answers

Rocker 1414