This puzzle is from the Irishman Owen O’Shea.
“The following puzzle illustrates a beautiful mathematical relationship involving a rectangle of any size and a random point within that rectangle that most people, including mathematicians, are unaware of.
The figure shows a rectangular room. There is a matchbox located 6 feet from one corner of the room and 27 feet from the opposite corner. The matchbox is also located 21 feet from a third corner.
How far is the matchbox from the fourth corner?”
See the Spot in a Rectangle Problem for a solution.

The following is another puzzle from the Irishman Owen O’Shea.
The following puzzle is from the Irishman Owen O’Shea.