A really simple but still a little non intuitive fact about the circumference of a circle.
Rope around the earth brain teaser.
From there it s not hard to believe that adding 3 feet to a rope around the actual earth would raise it almost 6 inches.
His neighbour also a fool wants to do the same only he wants the rope on sticks 1 meter above the ground.
A math brain teaser.
Band around the earth puzzle.
From the diagram it s pretty clear it s one foot.
In fact this brain teaser requires neither an exact measurement of the earth s circumference which in fact varies by many kilometers depending on which circumference you measure nor even an assumption that the earth has a circular cross sect.
A fool wants to tie a rope around the earth.
How much more rope.
You come along at night as a practical joke and add just 10 meters to its length one hundredth of one kilometer.
So he buys a rope of 40 000 km and ties it around the world.
The idea is to imagine the earth is a cube or just a square really and ask yourself if you added say 8 feet to the rope how far would that raise it above the square earth.