Geometry-lesson.github ((full)) -

Geometry Lesson Hub Reading time: 4 minutes

Drag the vertex. Prove them wrong. (Spoiler: On a sphere, it’s more than 180°. We’ll cover that next week.) 👉 [Visit the Live Demo] 👉 [Star us on GitHub]

Welcome to —where we stop guessing and start building. The Static Problem Traditional geometry lessons have a fatal flaw: they don’t move. geometry-lesson.github

Have a geometry concept that always tripped you up? Reply in the comments—we’ll build an interactive lesson for it.

Head over to (or check the repository on GitHub). Clone it, break it, fix it. And the next time someone tells you that the sum of the angles in a triangle is 180°, don't just nod. Geometry Lesson Hub Reading time: 4 minutes Drag

You can’t grab a triangle and stretch its vertices to see if the angles still add up to 180°. You can’t rotate a 3D solid to see why the volume formula works. You’re expected to memorize, not manipulate.

If you’ve ever tried to learn geometry from a static PDF or a dusty textbook, you know the struggle. You stare at a triangle on page 142, squint at the dotted lines, and wonder: "Does angle C really look like that? Or did the printer run out of ink?" We’ll cover that next week

Why Your Geometry Textbook Lies (And How GitHub Can Fix It)