Welcome to The Riddler. Every week, I offer up problems related to the things we hold dear around here: math, logic and probability. Two puzzles are presented each week: the Riddler Express for those ...

https://doi.org/10.4169/college.math.j.47.5.356 https://www.jstor.org/stable/10.4169/college.math.j.47.5.356 This paper provides a new, long proof of the Pythagorean ...

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. What is a triangle? We all know that a triangle is a three-sided shape — 1, 2, 3 sides. A triangle also ...

American Journal of Mathematics, Vol. 39, No. 1 (Jan., 1917), pp. 41-58 (18 pages) ...