The hourglass

A rectangle with two crossing line segments. What’s the minimal shaded fraction?

Scroll down for a solution to this problem.


The minimal shaded fraction is √2-1, which is approximately 41,4%.

Solution by Dr Rick.


The hour glass, a counting down
Made of sand
Heir of the clepsydra from Babylon
A sandtimer and 2 bulbs
Measuring our time and duration
Anywhere, regardless of orientation
Counting minutes, hours and seconds.
Sands of time run out for human condition
Using time
But not waste it!


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