Articles
Guides and resources about math education.
Triangles: The Strongest Shape and Its Angle Secrets
Why a paper square sags but a paper triangle cannot move: the three-point lock, the three name buckets, the folding proof of base angles, the outside-turn rule worth 40 plus 50, and the longest-side gate that stops a triangle from existing at all.
Tessellations and Tiling: Shapes That Fit Perfectly
A floor is a math proof you walk on. Why triangles, squares, and hexagons fill a surface with no gaps while the humble pentagon always leaves a hole — and how the 360 degree gatekeeper decides which shapes can tile at all.
Angles and Parallel Lines: The Hidden Rules of Geometry
A line crossing two parallel rails makes eight angles — and once you know one of them, all eight are decided. Meet corresponding, alternate interior, and same-side pairs, the carpenter's one-angle shortcut, and why the rules quietly prove that every triangle totals 180 degrees.
Surveys and Sampling: Asking the Right People
A survey's fate is sealed before the first answer is written — by who you ask, when you ask, and how you ask. Meet the mirror test, why 1,000 careful strangers beat 10,000 eager volunteers, and the three questions that catch a biased poll before it fools you.
Correlation vs Causation: Two Things That Travel Together
Two numbers rise together and our brains immediately write a story. Meet the correlation coefficient, the three-step detective test that separates a real cause from a coincidence, and the red flags that expose a hidden third factor before it fools you.
The Normal Curve: Why the Bell Is Everywhere
Heights, test results, measurement errors, and a hundred other things all pile into the same bell shape. Meet the normal curve, the 68-95-99.7 rule that makes it useful, and the one warning that keeps it honest: not everything is a bell.