In lieu of Readers’ Wildlife today, we have a puzzle, one posted (as the Guardian reports) by Russian Prime Minister, Mikhail Mishustin when he was visiting a science-oriented “sixth form” (what age of kids are these?) school. Matthew sent me a link.
Here’s the problem, and there’s a clue in both the photo below and in the Guardian article:
Construct a perpendicular from the (red) point on the circle to the diameter, without using any measuring devices.
In other words, given a circle with a diameter marked on it, and a point on the circle, can you find a way to draw a line from the point that hits the diameter at a right angle. (As marked in green above.)
The beauty of this question is the seemingly outrageous restriction not to allow measuring devices, which means that you cannot use a compass or a marked ruler. All you are allowed is an unmarked ruler to draw straight lines.
Matthew couldn’t solve it and, as I haven’t had my coffee, I’m not even going to try.
Here’s, a picture of Mishustin posing the problem (and giving a bit of a solution):