Welcome to The Riddler. Every week, I offer up problems related to the things we hold dear around here: math, logic and probability. There are two types: Riddler Express for those of you who want ...

Click to see a step-by-step guide. STEP 1: Use the ruler to draw a diagonal line from the bottom right corner of the paper to the top left corner. Mark the 90° right angles in the bottom left and top ...

As witnesses got up to testify to the Ohio legislature, it became clear there would be no consensus on Common Core math. Opponents to the new learning standards said they were developmentally ...

The shortest distance between two points is a straight line. This is one of the basic principles of Euclidean geometry. But we live on a spherical Earth, so we cannot travel the straight line path ...

THE principal novelties in this tract are the chapters on the orthopole (with some original propositions by the author) and on orthogonal projection (mostly after Prof. Neuberg). A pretty theorem in ...