Trivia
Subject:
Friday Puzzler -- Four DotsAlexY
In how many ways can you arrange four dots on a page (four points in a plane) so that there are only two distances between pairs of dots.
For example, if the four dots were the arranged in a square, the distance between any two dots is either the length of the sides of the square or the length of the diagonals.
If you find it too easy (I certainly didn't!), prove that you have found all such patterns.