fromwww.scientificamerican.com
1 week agoMath Puzzle: Falling Through
Some say the reason most manhole covers are round is that a circle cannot fall through a smaller circular hole. Which of these other two-dimensional shapes cannot fall through a hole that is the same shape but slightly smaller? Shapes 1, 2 and 3 can all fall through their own holes. Shape 4 cannot. Challenge problem: Can you find another shape that cannot fall through a slightly smaller hole of the same shape?
Science