Skip Discover Education Main Navigation

Classroom Resources > Brain Boosters
Favorites
Browse the Brain Boosters Gallery

 
  Reasoning

Round vs. Square		  
Q Why is it better for manhole covers to be round rather than square?


  
A You can turn a square manhole cover sideways and drop it down the diagonal of the manhole. You cannot drop a round manhole cover down the manhole. Therefore, round manhole covers are safer and more practical than square ones.

Based on "Manhole Covers," found at http://einstein.et.tudelft.nl/~arlet/puzzles/
lateral.html,which citesChallenging Lateral Thinking Puzzlesby Paul Sloane and Des MacHale, distributed by Cassell in the UK and by Capricorn Link in Australia.